The Demon Lord is immune to logic and strength, but he has a hidden weakness: he hates emotional instability. When Merle enters the final battle by accident (looking for her lost cat), her constant whimpering and apologizing trigger the Demon Lord’s misophonia so badly that he surrenders just to make her stop crying.

: A reincarnated "berserker" who accidentally becomes too powerful for his supposed NPC role.

takes the concept of a Mob character and flips it on its head. The protagonist isn't trying

The Frenzied Mob Character Unknowingly Destroys the Main Story

How the "Main Characters" of the world react when their scripted victories are stolen by a passerby.