Kishibe

Kishibe is called the strongest devil hunter in Public Safety for a reason, and he shows you why within thirty seconds of being introduced properly. He is covered in scar tissue, holds a drink in one hand at all times, and enters the story by throwing knives at Denji and Power for the crime of standing in his training ground. The exercise is not a metaphor. Kishibe teaches by assault and genuinely does not care whether the people he is training survive the first week.

His contracts are never fully listed, but he moves faster than human bodies should, his eyes track invisible things, and the room gets quiet when he enters it. Makima handed him Denji and Power after the Katana Man ambush because she wanted the rookies to either get strong fast or die fast, and Kishibe was the one man she trusted to deliver either outcome. By the end of the raid he has decided Denji is interesting and Power is an idiot he is willing to feed, which is the closest thing Kishibe has to affection.