Bedlam, Vol. 1 by Nick Spencer

A reformed mass-murdering mastermind once known as Madder Red resurfaces as a fragile, medicated civilian who begins assisting a skeptical police force when a new string of ritualistic killings grips his decaying city; as he hunts a killer who mirrors his own past atrocities, he wrestles with fractured identity, lingering compulsions, and the uneasy question of whether genuine redemption is possible for a monster.