Roman Sionis is a crime-lord who was accidently knocked into a vat of chemicals that were being used to make drugs, and the chemicals formed a black mold that hardend to his face. He became the Black Mask and wanted revenge on Batman, who accidently knocked him in. In Lobo Part 2, Black Mask hires Lobo to kill Batman, but Robin stops him. Black Mask then fights Batman himself, and gets arrested. Later on, in Code: Black, Black Mask tries to release the drug he helped Johnathan Crane make, Fear Gas, upon Metropolis, but Nightwing stops him, and Black Mask is last seen falling to his death off a bridge. He is played by actor Jason Isaacs.
- After his death, he is refferenced in Superman Part 1 by Beast Boy, who says that, after he destroys a secret warehouse where they are making drugs, "crazy guys like Scarecrow, Joker, and Black Mask couldn't get away with it, then how could a bunch of street thugs think THEY can get away with it?"
- In Metropolis: The Video-Game, when Robin is crawling through an air vent, you can see Black Mask's original wooden mask in there.
- In the video-game, you can also see, on the bridge Black Mask died on, graffitti that says "I'LL BE BACK!" written in black spray-paint.