Azrael

Born Michael Lane, Azrael was once a police officer based in Gotham City. Lane was once part of an initiative to create "the ultimate crime fighter," however it turned him into a criminal. Once captured by Batman, Lane confessed his sins to a priest of the Order of Purity. He was then recruited to "fight evil as their crusader Azrael" while wearing the Suit of Sorrows and using the Sword of Sin. The Suit of Sorrows will defeat Lane if he does not keep his soul pure.

Batman: Arkham City
Batman encounters Azrael many times throughout his "incarceration" in Arkham City, where he gives cryptic statements before disappearing and leaving an ambiguous symbol. Once all the symbols are collected, they form a map leading Batman to the Gotham Cathedral. At the church, Azrael reveals that he has been sent to observe Batman, believing he is a warrior foretold by an ancient prophecy. He reveals he was sent by the Order of St. Dumas to deliver a prophecy to Batman. He tells how the city will burn, and that Batman is the "warrior" who will save Gotham, but will fall in the process. Batman remains skeptical of Azrael's prophecy claiming he does not believe in fairy tales, but Azrael holds firm in his belief, telling Batman they will meet again as he departs Arkham City.