闇やみ堕おち

noun, noun or participle which takes 'suru'

falling to the dark side; turning evil

Colloquial term, especially in fiction (anime, manga, games), for a character who was originally good turning evil or joining the antagonists. Often used with する to describe the action.

• あのキャラ、途と中ちゅうで闇やみ堕おちするんだって。

  I heard that character falls to the dark side partway through.

• 闇やみ堕おちしたヒーローがラスボスになる展てん開かいはよくある。

  It's common for a hero who has turned evil to become the final boss.