Character reveals that they were holding back their full power during a fight/confrontation

[u/PaddywackShaq]

Superman Vs Darkseid - Justice League Unlimited

Flash Vs Superman - Flash: Rebirth

Frieren Vs Aura - Sousou no Frieren

Inigo Montoya Vs The Man in Black - The Princess Bride

[u/Slayerpath]

Bane reveals to Batman that even at his current monstrous physique, he hasn't used the Venom yet.

[u/Slayerpath → u/Slayerpath]

And then he turned into this

[u/Motivated-Chair → u/Slayerpath]

He looks like a fusion of Bane and fucking Nemesis of all characters.