Oh god, this is horrible. Because three people instantly jumped to mind.

If we are talking about most hated as in a character I dislike the most (Equius), I would grab the nearest blunt object and beat the shit out of him.

If we mean hated as in the one that scares me shitless (Jack Noir), I would run away, move to Australia, and hope he never finds me.

If we mean hated as in I found this thing the most horrible thing in existence (’Lil Cal) I would burn down the entire house