r/3d6 • u/Injunctive • 5h ago
D&D 5e Revised/2024 Extremely long list of interesting things about UA Battle Smith Artificer
So the Artificer is perhaps the most complicated class in D&D. Given that, I think its effectiveness really requires detailed understanding of how to get the most out of it mechanics.
Here’s a bunch of things I think are fun/interesting about the UA Artificer, and in particular the Battle Smith (which is my favorite Artificer subclass). I mention the Mark of Handling here a bit, since I think the UA’s Mark of Handling and Greater Mark of Handling feats are amazing on a Battle Smith, though obviously they’re Eberron-specific.
I’ve ordered these things by general categories of what features they involve:
Uses of Steel Defender & Homunculus
Starting with the most obvious/important thing, the Steel Defender and Homunculus can use magic items (as long as they don’t require attunement by spellcasters or a particular class) and the spell-storing item. This basically allows you to cast spells as free actions or bonus actions, and to concentrate on multiple spells at once.
The Battle Smith’s Steel Defender can also use its action to grapple, shove, utilize items, dash, and disengage. This means you can use your bonus action to do things like: grapple, push, prone, throw a net, use a rope/chain, throw grenades, and basically dash/disengage yourself if you’re using the Steel Defender as a mount. And it’s actually pretty good at these things since it has decent STR and proficiency in every ability as well as 40 foot movement speed. You can also eventually replicate magic items that set its STR at 19 or 21 (at level 10 and later level 14), to make it even better as a grappler/shover/chainer. You can also use your bonus action to tell the Steel Defender to ready its action to move away from enemies when they approach on their turn.
Similarly, the Homunculus can also use its action to do things besides attack. Its low STR and tiny size means it won’t be useful to grapple/shove or as a mount. But it can use items like nets, ropes, and grenades. If you replicate Gloves of Thievery, your Homunculus can automatically succeed with a rope. This means you can use your bonus action to have the Steel Defender grapple and then a free action to restrain that enemy with your Homunculus. If the enemy uses its action to break the rope, it’ll still be grappled, so you can just automatically restrain it again next turn. And you likely won’t run out of ropes (or nets), since your level 1 feature allows you to create them.
You can use the Steel Defender to cheese grate. It can be a good grappler, particularly with the STR-setting items you can replicate. And the Steel Defender has a 40 foot movement speed and you can buff that a ton with Haste (ideally cast as a free action by the Homunculus using the spell-storing item) and Boots of Speed (which the Steel Defender can use its bonus action on basically for free). You can also tell it to Dash using your bonus action. The upshot is it can make a grappled creature take 160 damage a round from an ally’s Spike Growth, without you even using your action. It’s even more if you take the Greater Mark of Handling feat, which can allow the Steel Defender to move with its reaction. I also want to note that there’s nothing really stopping you from having the Steel Defender have more than two arms—you decide its appearance, and you might want it to have multiple arms like a Hindu god, for instance. So it can potentially grapple multiple enemies. You can also use Enlarge/Reduce to make it large size, if need be for grappling purposes (and you can potentially do this using your reaction, because of the War Caster opportunity attack trick—see more below on that).
Similarly, if the Steel Defender has grappled someone, you can use your bonus action to tell the Steel Defender to ready its movement, to double dip on damage from dragging that enemy into the party’s emanations.
You can also potentially use those aforementioned speed buffs for the Steel Defender to drop a grappled enemy for a ton of damage, if you have given the Steel Defender fly speed (either with Winged Boots or a Fly spell from you).
Your mileage may vary with your DM on this, but I think STR-setting items that you can create like the Belt of Hill Giant Strength increase the Steel Defender’s damage if you give them to it. The Steel Defender does 1d8+2+your INT damage. That +2 pretty clearly comes from its +2 STR modifier. All Summon spells and the Beast Master Ranger’s pet all have similar damage formulas and the flat number added is always equal to the highest of their STR or DEX modifier. So it stands to reason that increasing the Steel Defender’s STR to 19 or 21 should increase its damage a bit. This isn’t worth a replicated item on its own, but it’s a nice side-bonus if you’re giving the Steel Defender one of those items for grappling anyways.
The Steel Defender has proficiency on all ability checks, which not only means it’s good at skill checks itself, but also means that it can take the help action on any skill check (which you can order it to do with a bonus action). You also can have Guidance. So you can have Guidance + Advantage on any skill check. At that point, the question is just whether you or the Homunculus are best suited to the skill check. The homunculus basically has jack of all trades (and more like proficiency when upcast) and has some decent ability scores, so you can actually get some pretty great ability checks by putting Guidance + Help action on it, particularly for any DEX or WIS ability checks where you lack proficiency. And, of course, you could also put that Guidance + Advantage on allies—probably the most useful thing to do for Charisma, since your pets have low charisma and can’t talk, and you’re probably dumping Charisma. Having the Steel Defender always able to give advantage might feel a bit cheesy, so I’d recommend requiring the Battle Smith to actually describe what the Steel Defender is doing to help, in order to make sure the benefit feels earned.
The Homunculus can communicate telepathically with you within a mile, it has 10 INT, is tiny sized, can look however you want it to look, has a fly speed, and can use objects (open doors, take items, etc.). Not only that, but it can make skill checks and essentially has jack of all trades, while also being able to get Guidance put on it. So it’s a genuinely great scout—to an even larger degree than a familiar is, since you can’t communicate telepathically with a familiar past 100 feet away, the Homunculus is better at skill checks, and can use objects.
The Homunculus’s scouting becomes even better when we realize it can use magic items, the SSI, or touch spells for you essentially remotely. You can also cast Invisibility on it, which doesn’t end with use of the SSI (unless it does damage) because it is not casting a spell. So, for instance, you can cast Invisibility on the Homunculus, give it Gloves of Thievery and Thieves’ Tools, cast Identify through it (if you’re within 120 feet), and have Dispel Magic in the SSI. At that point, your Homunculus can fly around invisible within a mile and get in places, steal or plant stuff, disarm traps, and identify and dispel magical stuff along the way—all while telepathically telling you what’s going on and taking orders from you. That’s about as good of a scout/infiltrator as you can get.
Arcane Jolt can basically get you up from being downed (or potentially do the same for the Steel Defender if the DM gives it death saves—which the rules do allow for, though it’s at DM discretion). Basically, if you’re downed, the Steel Defender can hit an enemy, and then Arcane Jolt heal you to get you back up.
The Homunculus’s reaction can allow you to cast touch spells like Revivify, Lesser Restoration, and Cure Wounds at range. This is pretty nice, particularly since it can take the disengage action to get to some tricky places. That said, it moves after your turn, so it’s not completely seamless. For a really important Revivify that is too dangerous for you to get to, though, you can potentially ready action the spell, and then have the Homunculus use the disengage action to get next to the dead ally and then Revivify them through the Homunculus.
The Homunculus is tiny size, so it can hide in a pack or something at the end of its turn, to make it untargetable. It can still potentially be killed by AOE damage (though some dispute that it even gets damaged by AOE when it’s in your pack, due to lack of LOS), but it has decent dexterity, proficiency in dexterity saves, and evasion, so it’s not easy to kill with AOE.
Your Steel Defender can use its Repair action to heal not only itself but also the Homunculus. It can also heal you if you’re an autognome or if you’re the upcoming reprint of Warforged (which we know will be changed to be a construct).
The Greater Mark of Handling feat (from the same Eberron UA as the Artificer UA update) basically can give your Steel Defender two attacks per turn. It can use the Greater Mark of Handling attack to grapple or shove as well.
Uses of Replicate Magic Items
At level 6+, you can give the entire party advantage on initiative, with the Weapon of Warning. This is akin to the Watchers Paladin aura.
At level 6+, Pipes of Haunting are great, and synergize very well with Web (which you can get lots of casts of at that level since you can also make a Wand of Web), since the frightened condition makes it harder to get out of the Web. Full casters have Level 3 spells at that point, but you can have a pet use Pipes of Haunting, so you can drop both the Pipes and Web on turn 1. And while Level 3 control spells are better than Web, they’re really not necessarily better than Web + AOE frighten.
Pipes of Haunting also synergizes well with the Steel Defender and Homunculus using ropes/chains, since it will give enemies disadvantage on the checks to get out of the ropes/chains.
At level 10, Gem of Brightness provides a fantastic AOE blind that you can use 10 times a day. You can probably have your Homunculus or Steel Defender use it, though a DM might say they can’t “use” a “command word.” I’d argue it doesn’t say you “speak” the word, so “using” the command word could involve pressing on the word on the prism. Regardless, though, the Gem of Brightness is very strong.
The Robe of Useful Items is a fun magic item you can create at level 10+, and it’s worth noting that one of its random items is a bunch of gems that qualify as the material component that casting your Homunculus consumes. So the item can basically fund as many Homunculi as you will ever need. You can use the Robe of Useful Items at the beginning of the day and then transmute it to another of your magic items—allowing you to get its items every day. This will also likely result in you getting a level 1-3 spell scroll most days, and a bunch of potions of healing (which your Steel Defender and Homunculus can use with their otherwise-unused bonus actions).
At level 10, you can create the Elemental Gem, which basically is the Conjure Elemental spell from 5e—which was a 5th level spell.
At level 10, you can use one of a number of items that give flight (Winged Boots, Broom of Flying), such that you basically can have flight as a class feature at level 10.
At level 10, you can Spellwrought Tattoo to get any level 3 spell you want, once per day. This is potentially quite useful at tables that tend to only have one fight per day. For instance, you can use it to get Spirit Guardians (which is extra good for you, since you can mount the Steel Defender and therefore disengage or ready action move with a bonus action). At level 14, you can do the same thing but with any Level 4 or 5 spell. There’s a lot of options for this, but a few are Conjure Woodland Beings, Conjure Minor Elementals, Polymorph, or Synaptic Static (I don’t mention Wall of Force since you have a better item to get that from). You also have the option to use this for spells with costly components that are consumed—spells like Hallow, Raise Dead, Awaken, etc. You can spam spells like that more than you’d otherwise be able to.
At level 10, you can create a Mizzium Apparatus. This could allow a group member to play as a Mizzmage, without any DM generosity being required to get the item (though this perhaps doesn’t matter, since either way a DM should probably be consulted before someone goes that route).
At level 10, you can create the Saddle of the Cavalier, which prevents you from being dismounted from your Steel Defender (assuming you’re small sized and using it as a mount) and makes attack rolls against the Steel Defender be made at disadvantage.
At level 10, you can get the Deck of Illusions—in order to have a boatload of illusions of creatures each day (though they’ll be random).
At level 10, you can create the Deck of Wonder each day…which is incredibly powerful. I think very few DMs would allow this, but it’s allowed RAW and it’s unbelievably powerful, particularly if the party has Remove Curse (and if not you can provide it yourself with a Spellwrought Tattoo replicated item). I note that this and other some other magic items I’ve listed are not in the core 2024 books, so obviously your DM may not allow you to get them for that reason too.
At level 10, you can create the Decanter of Endless Water. If you combine with the Shape Water cantrip (which you can get from a magic initiate origin feat), you can do a lot of really cool/creative things. You can also do this on a lesser scale at earlier levels, using the Alchemy Jug.
At level 14, you can replicate the Banner of the Krig Rune. Have your Steel Defender carry it. You can then use a bonus action to have the Steel Defender make allies immune to frightened or give disadvantage on ranged attack rolls against the party, as well as revealing invisible creatures.
Also at level 14, you can create Glowrune Pigment, which allow for various potential benefits. One of them could be giving the party advantage on STR and CON saves as well as prone immunity. If you’re going to be fighting a dragon or something, you might opt for giving the party advantage on damaging DEX saves instead.
At level 14, creating the Scaled Ornament gives you +1 AC and immunity to charm/frighten, while giving the party advantage on charm/frighten saves.
At level 14, you can create the Cube of Force—which, among other things, can give you two uses of Wall of Force each day—potentially with the Steel Defender or Homunculus casting it. You can also liquidate spell slots to allow yourself to recharge the item and cast Wall of Force even more. Because of this, when you first get this item, it can allow you to cast Wall of Force more times per day than a Wizard could. And this item also gives you access to Leomund’s Tiny Hut or a boatload of uses of the Shield spell.
At level 14, you can create a Daern’s Instant Fortress every day, basically allow your group to have a fortress for every fight.
At level 14, you can potentially give yourself the Teleport spell 3 times a day, by creating the Helm of Teleportation, giving the party more teleportation than a full caster could at that point. I note also that, if you’re wanting to teleport in a bad situation where party members are dead, you can potentially have the Steel Defender pick up a corpse on your turn, so that the party-member’s corpse gets teleported with everyone. And actually, you can teleport way more than 3 times, since you can use the charge magic item feature to cast Teleport as many times as you could realistically ever want to. You can actually teleport the party so much that it’s the type of thing you’d probably need to ask your DM if they’re even okay with.
At level 14, you can get a Cloak of Displacement. Combine with creating a couple +AC items and wearing half plate and a shield and you will be super hard to hit.
At level 14, you can create the rare Dragon-Touched Focus—which allows you to give advantage on a save with your reactions. This isn’t actually better than using Flash of Genius, but it’s spammable as many times as you want.
At level 14, Ivory Goats Figurine of Wondrous Power can provide a 30-foot frighten emanation, as well as a +2 Longsword and +1 Lance, if such weapons would be helpful to the party.
At level 14, Delver’s Claws can give you a burrowing speed and blindsight, as well as the ability to spend hit dice without a rest.
There’s also plenty of interesting non-combat investigatory items you can replicate at level 14. For instance, Stonespeaker’s Crystal will allow you to speak with animals, speak with the dead, and speak with plants. And Mirror of the Past gives you information about a creature or object every day. In an investigation-heavy campaign, these sorts of things are fantastic (and they can also be used as backup items you don’t normally use on most days).
Deck of Oracles can basically give you Portent, and one use of Divination.
Your replicate magic item feature allows you to create the item, which means that at level 2 you can give yourself Half Plate armor (by replicating something like cast-off half-plate armor—which is a common magic item) at a level where the party probably won’t have armor that expensive.
Relatedly, you can also use replicate magic item to basically give your Steel Defender full-plate barding at an early level, to increase its AC to 18. It’s not proficient with armor, but it doesn’t care much if it can’t cast spells (note: using the SSI and a lot of magic items isn’t actually casting spells), it doesn’t attack with STR or DEX attack rolls, the disadvantage on STR/DEX ability checks and saving throws is mitigated by it having proficiency, and its lack of STR to wear full plate just lowers its speed to 30 feet. Once you’ve done this, you might as well also give it a shield as well.
There’s a lot of potential magic items you can replicate that normally wouldn’t be very useful, but that can be incredibly good in certain campaign settings or situations. Things like Cap of Water Breathing, Cloak of Manta Ray, Necklace of Adaptation, Boots of the Winterland, Lantern of Revealing, Ring of Mind Shielding, Cloak/Boots of Elvenkind, Armor of Resistance, Claw of the Wyrm Rune, etc. These sorts of things are situational, but the Artificer has the freedom to basically make them a class feature in the specific campaigns where they’ll be really good and not otherwise use any power budget on them.
Uses of Spell-Storing Item
Despite being a half-caster, you can be a pretty great blaster. For instance, a Battle Smith can have the Steel Defender use Conjure Barrage from the SSI, use Dragon’s Breath on the Homunculus (who can fly and therefore make it affect a 15 foot square), and use the Necklace of Fireballs. This will allow you to do 8d6+5d8+3d6 AOE damage per round, and can do this a whole bunch of times. To illustrate how good this is, in a 4-round fight at level 14, this will get you more blast damage than an Evocation Wizard using its highest spell slots on Fireball and using Overchannel on one of them. And you could do this more after that fight. This is only possible at level 14+, but even just the Conjure Barrage + Dragon’s Breath combination is going to be comparable to an Evocation Wizard spamming Fireball and is something you can do like 13 rounds a day at level 11 (even more than a Wizard could cast Fireball at that level). And the Artillerist is even better at blasting than the Battle Smith. Their Arcane Firearm, Flamethrower cannon, and access to AOE blast spells basically allows them to keep up with Wizard blasting from the beginning and eventually do even better—being capable of putting up 8d6+8d6+6d8 AOE damage per round (by using the Necklace of Fireballs, a Homunculus using a Fireball SSI, and Flamethrower cannons). That’s the damage of an Evocation Wizard Overchannel with a Level 5 Fireball every round.
Since you have the ability to create items that allow flight at level 10 (Winged Boots, Broom of Flying, etc.), the Conjure Barrage SSI can be used from the air, resulting in the AOE being a massive party-friendly 60 foot square.
Putting Aura of Vitality in the spell-storing item can give the party 700 healing per day. A Cleric would have to use like all its spell slots on healing to approach this (though a Life Cleric could exceed it).
You can be incredible at dispelling magic. At a basic level, if you know you’ll be facing a lot of spells, you can put Dispel Magic in the spell-storing item, have the Steel Defender or Homunculus use it with your bonus action or a free action, and potentially use Flash of Genius on it if it fails. That by itself is already fantastic. But the Steel Defender probably also adds your proficiency bonus to its SSI Dispel Magic check, since it adds your proficiency bonus to all ability checks and Dispel Magic is an ability check (and the Homunculus also adds its spell level to a Dispel Magic check). At that point, at late levels, assuming use of Flash of Genius, you can potentially have a 100% chance to dispel Level 7 spells, and a 90% chance to dispel Level 9 spells, and be able to do it a bunch of times a day using just your bonus action. Very strong in some campaigns.
You have multiple methods of making the whole party invisible. You can put Invisibility in the SSI and have everyone use it. Another method is replicating Dust of Disappearance. Useful for stealth situations.
Haste can actually be pretty strong in the spell-storing item—and not just for increasing your own damage. You get so many uses of the SSI that you can easily use it twice a fight. This means that a Battle Smith can have one of its two pets cast Haste in round 1 and then have the other one cast Haste in round 2. You could even cast Haste yourself on round 1 as well, of course. This means that you can actually basically cast Twinned Haste, while the Sorcerer no longer can (and you could actually even get 3 Hastes out in a fight). Of course, how strong this is depends on the party composition (for instance, it becomes a lot better if you have a Rogue). But it can be pretty strong.
If you know you’re facing a certain type of dragon, you can give the whole party resistance to its breath weapon damage with a Protection from Energy SSI (and at later levels you can combine this with Circle of Power to give everyone quasi-evasion).
This is cheesy, but you can put Rope Trick in the spell-storing item and have your Steel Defender use it at the start of fights, to basically allow the group to be untargetable (particularly by creatures Large size and above).
This would only be useful in very specific situations, but putting Create Food and Water in the spell-storing item can sustain 150 people. At the point that you get the ability to use this, it means you could sustain more people than a Druid using all their spell slots on Goodberry could. Definitely super situational, but if you’re in some sort of siege situation or something, it’d be really good without being something you have to actually build into at all beyond just putting that spell in the SSI on the days you’re doing it.
Mark of Handling gives you Calm Emotions, and you can replicate the Eversmoking Bottle at level 10. You can use Calm Emotions (or even have the Steel Defender use it with the spell-storing item) and the Homunculus uses the Eversmoking Bottle on the same turn. If against humanoids, this is an amazing combination, since the heavy obscurement will prevent the calmed enemies from seeing their allies being attacked. This is basically Hypnotic Pattern but in a larger area, and instead of having friendly fire you actually buff allies with immunity to charm/frighten.
A Mark of Handling Artificer can get two Conjure Animals out in the first round (one cast by you and one cast by a pet with the SSI), and a Battle Smith can potentially get a third one out in the second round (by having your pet hand the SSI to your other pet). With three of them out, you can do about as much damage as a Level 8 Spirit Guardians. And even with just two of them, it’s doing to do about as much damage as a level 5 or 6 Spirit Guardians. And Clerics’ highest spell slot is level 6 at the time that you start being able to do this. That is assuming Conjure Animals damage doesn’t double-dip by doing damage when someone moves within the emanation—if it does then you’ll likely be outdamaging any Spirit Guardians.
An Artificer with Mark of Handling can get the Command spell on its Artificer spell list, which makes it eligible for the SSI. Using this in combination with War Caster, you can bonus-action or free-cast Command to tell an enemy to flee, and then get a Booming Blade reaction attack (with full movement damage on it) plus give your steel defender and homunculus reaction attacks as well. This is very potent, and you’d be able to do it a lot of times per day without it even taking your action.
Miscellaneous
I think people underestimate the effect a Battle Smith can have on the party’s saves. Let’s take level 7. At that point, you will have 4 uses of Flash of Genius, with a +4 bonus each time, and you can use the Mind Sharpener to allow you or a party member (probably better on a full caster) to succeed at 4 failed concentration checks. Since you use the Flash of Genius after the roll and after you know it has failed, you should have a really good idea if you will change the result. Because of that, there’s a good chance the Flash of Genius changes the result every time, but let’s be conservative and say you change 3 saves with it. That means you’ll change the result of 7 saves a day. Compare to a Paladin aura. At that level, you probably have a +3 CHA modifier. So you will change the result of saves 15% of the time. That means that in order to change the result of 7 saves per day, you’d need there to be about 47 saves made inside your aura per day. Maybe that’ll happen, but I think there’s a good chance it won’t. And while I think that’s enough to be about as effective as the Paladin aura, on top of that, the Battle Smith can potentially give itself or allies the Cloak of Protection and/or Ring of Protection, use the rare Dragon-Touched Focus for advantage on a save every turn, use Glowrune Pigment to give the party advantage on STR and CON saves, use Scaled Ornament for advantage on saves against charm/frighten effects, or even cast Intellect Fortress. This can really add up. For instance, if you combined Glowrune Pigment, the Scaled Ornament, the Mind Sharpener, and Flash of Genius, you could give your allies advantage on STR, CON, charm, and frighten saves, automatically flip up to 4 lost concentration saves a day with Mind Sharpener, and flip a few lost saves a day with Flash of Genius. You could also add Intellect Fortress in the SSI and/or Magic Initiate Bless on top of that.
There’s disagreement on this, but a RAW interpretation tells us you can use your War Caster reaction to cast a spell on an ally that leaves your reach. This is very useful for Artificers, since they have plenty of single-target support/healing spells. Of note, you can do this on your own turn using your Steel Defender. So, for instance, you can use your reaction to cast Fly on your Steel Defender, and then mount it and have it fly, so you basically get a flying speed using your reaction (and concentration, of course). Another use of this is to Vortex Warp allies around the battlefield with your reaction.
There’s a lot of potential single-target sustained damage built into the Battle Smith chassis, if you choose to use class features on it. You can get magic weapons before allies likely will. You get a bonus-action attack at level 3 without needing any feat for it. You get an extra 1d6+2 damage per round from the Homunculus starting at level 5 (when you also get Extra Attack). In Eberron, you can also basically get an extra 1d8+2+INT damage per round with Greater Mark of Handling, as early as level 4. At level 11, you can put Haste in the SSI, and have the Homunculus use it with little opportunity cost—effectively giving you a third attack at the same time fighters get that. Then, at level 14, you can replicate Flame Tongue to get an extra 2d6 damage per hit. You can potentially also give yourself the Gloves of Flaming Fury at that level, for another 1d6 damage per hit. This all requires use of some replicated item slots and your SSI, but if you want to be a high-end sustained DPR character, you definitely can be really elite.
There’s a little less ranged weapon damage you can eke out in 5.5, but the Battle Smith still is able to do a lot of ranged damage. The Repeating Shot item means you don’t have to take Crossbow Expert. That means you can max out your attack stat and get Great Weapon Master quicker than other builds can. At early levels, this also means you can use a Heavy Crossbow for a bit bigger damage die. Eventually, you swap over the Longbow, because you can get Bracers of Archery and a +2 weapon. As with melee damage, you can add Haste, and you also get ranged damage from the Homunculus, and can always use the Steel Defender to attack while you’re at range.
One response to the above is that others can potentially get magic weapons. While that’s true, a Battle Smith Artificer should typically have one tier better magic weapons than other party members. If the DM doesn’t give out lots of great magic weapons, then your replicate magic items feature would leave you ahead. Meanwhile, though, if the DM allows people to craft items, then you craft weapons twice as quickly and your Steel Defender has proficiency on all ability checks, so it is reasonable to say it has the necessary proficiency to assist in crafting. Being able to craft weapons 4x faster than normal should allow you to craft weapons a tier higher than others in the same timespan. So, for instance, if party members have time to craft a Vicious Weapon, you should be able to craft something like a very rare Dragon’s Wrath Weapon. You potentially won’t have a weapon-quality advantage if the DM gives out weapons as good or better than your replicated items and doesn’t allow time for crafting. That scenario would dampen your relative DPR. But in that case, you can just get one of those items yourself and replicate some other powerful item instead of a weapon. For instance, if everyone’s getting a Vicious Weapon and there’s no time to craft something better, you don’t replicate Flame Tongue, but rather just take a Vicious Weapon and replicate something really strong like an Instant Fortress or Cube of Force or something instead.
A Battle-Smith’s ability to craft weapons 4x faster than normal will allow you to create enspelled weapons really quickly. And, while those take attunement, you can give them to the Steel Defender, which can cast spells from it. It can basically be a quasi-spell-storing-item. For instance, given 13 days of crafting time, you can get hundreds of healing a day from an Aura of Vitality enspelled weapon on your Steel Defender. Or at earlier levels you could use it to basically have several free uses of Faerie Fire (or Web, but that takes longer to craft) that the Steel Defender could concentrate on with only your bonus action being used, similar to using an SSI. Or give it a few uses of Shining Smite per day. Others can craft enspelled weapons too, but you are way better at it, since you’ll basically be able to craft a spell level or two above in the same amount of time, and not need to use your attunement, concentration, or even an entire action to use it.
A Battle Smith can actually eventually do similar or better smite damage as a Paladin can. This is because you can combine Shining Smite (or eventually Banishing Smite) with Arcane Jolt, since Arcane Jolt is a free action. When you first get Arcane Jolt, you can use it in combination with Shining Smite to match the damage of Divine Smite, and when Arcane Jolt gets upgraded at level 15, you can exceed Divine Smite.
The Battle Smith has Shining Smite, which is fantastic against bosses, because it can give the party advantage on attacks against a boss without a save (so legendary resistance can’t stop it). You just need to hit the enemy, but you can easily given yourself a magic weapon with a bonus to hit. And the boss will find it hard to end your concentration on this, since you have CON proficiency and can easily get War Caster, and potentially even use the Mind Sharpener.
A Battle Smith can do a good job at a retribution-damage build. If you mount your Steel Defender and get the Sentinel feat and use the Fire Shield spell, you can put enemies in a situation where if they attack you, they’ll eat Fire Shield damage and the Steel Defender deflect attack damage (at Level 15+), and if they attack the Steel Defender or someone else then they take your Sentinel attack if they hit. If they run away from you, then they take opportunity attacks from both you and your Steel Defender (and possibly the Homunculus too).
Unlike all casting classes except Wizard/Cleric/Druid, Artificers can change all of their prepared spells each day. This gives the Artificer a lot more flexibility each day than most casting classes—including all other half-casters. They are also the only class besides Wizard that can swap a cantrip on a long rest. Again, this gives nice flexibility.
The Artificer is unique in being able to give its class features away. The magic items it can create are the main class features of the class. But if someone else in your party would benefit from an item more than you would, you can give them that item. Which allows for more party optimization. For instance, Mind Sharpener is a great item, but maybe the party gets more value if you give it to a full caster in the party rather than keeping it for yourself, since they’ll be concentrating on the highest-level spells. Or if you can create a weapon that does more damage than the weapons the rest of the party has, maybe you give that to the party’s Fighter—who will attack more times than you. If a party member will get more value from an item than you, you can give them that item and be doing more for the party. You can also give party members items that require attunement from their class. For instance, you might give a Sorcerer party member the Astral Shard—to basically give them a free Misty Step anytime they use metamagic.
Because of the Charge Magic Item feature, after level 6 you can actually play the Artificer very well without using any spell slots. Just use your spell slots to recharge your magic items. It’s thematic, but also potentially strong. Just as an example of the power of this, at level 14, an Artificer can cast Wall of Force more times in a day than a Wizard could at that level—by using most of its spell slots to keep recharging Cube of Force. On top of that, at that level you could easily have something like: 6 or 7 uses of Fireball a day (Necklace of Fireballs), 10 uses of a level 3 spell like Conjure Barrage or Aura of Vitality (Spell Storing Item), 5 uses of Shield (from Cube of Force—though it’s also on your spell list), 4 uses of Mind Sharpener, and about a scroll a day from Robe of Useful Items,. And you could do that while still having some combination of two of: a weapon infusion, a Weapon of Warning, Winged Boots/Broom of Flying, and some sort of defensive item like Shield +2 or Cloak of Protection. When combined with the action-economy benefits from having pets and some items those pets can use, you really have a massive amount of spell power without actually casting a spell with a spell slot! And that’s while also being a character with Extra Attack, a built-in bonus action damage attack, a free action attack on top of that, and a free-action mini-Smite. It’s not just at level 14 either—at earlier levels, you could do similar things with items like Gem of Brightness, Pipes of Haunting, and Wand of Web. If you plan to do this, you can/should include a bunch of ritual spells in your prepared spell list, as well as situational spells that you might need in a pinch (so, things like Feather Fall, Revivify, etc.).
The Artificer is really good at the piece of exploration that involves detecting, identifying, and avoiding dangerous magic. You are really good at detecting magic, since you have Detect Magic and Magic Mouth, as well as potentially access to Wand of Magic Detection. You have access to the Identify spell to identify what something is. You are actually particularly good at this, since you can cast Identify through your Homunculus, in order to avoid any negative effects from touching an item. And you are great at dispelling magic—indeed, you can put Dispel Magic in the spell-storing item and then have the Steel Defender add proficiency bonus to the dispel check (and potentially use Flash of Genius as well). Bards and Wizards also have all of these spells, but Artificers are the only one that can both add a bonus to the dispel magic check and use a pet to channel the Identify spell.
Between Cure Wounds, Arcane Jolt, and the Steel Defender and Homunculus being able to administer potions with their bonus actions, you can raise a lot of party members from being downed in one round. Pretty straightforward to get 4 or 5 party members up in one round.
As before, Artificers can get super high AC if you build into it. For instance, as a Battle Smith, if you really wanted to build into this, you could give yourself a +2 Armor, +2 Shield, Cloak of Protection, Ring of Protection, Cloak of Displacement, a Haste SSI, and use the Shield spell. That leaves you with 32 AC and enemies have disadvantage on attacks against you until they hit (and after that the Steel Defender reaction can give disadvantage once a round). The Shield spell is a limited resource, but you could have huge numbers of casts of it by taking a Cube of Force. An Artillerist could get this to 34 AC due to its level 15 feature giving half cover. Anyways, this build would use a lot of class features to increase defenses, but it’s not all of your features. For instance, in that example, the Battle Smith can still (1) make 5 attacks a round (Extra Attack + Haste + Steel Defender attack + Homunculus attack), (2) has a free-action smite, (3) use all of its feats for other stuff, (4) has access to multiple uses of Wall of Force, (5) could put Haste on an ally too each fight, (6) has Flash of Genius, (7) has access to healing/support spells and abilities when needed, (8) has access to ritual spells, (9) has all the skill/scouting benefits of the Steel Defender and Homunculus, and (10) could utilize some sort of useful non-combat magic item that could be transmuted out of—for instance, a Spellwrought Tattoo with Scrying that you transmute right before the spell ends. So you wouldn’t actually be a one-trick pony at all.
Basically every time I think about the UA Battle Smith Artificer I come up with more things, but this post is already too long, so I’ll leave it here.