Onyx is right-hand woman to The Heretic, an adult clone of Damian Wayne. After the Heretic is killed by Talia al Ghul for desiring to steal the real Damian's memories, Onyx appears to burn with a silent hatred of Talia. After Talia managed to escaped into her auto pilot vessel, she attacks her master's killer on a hovercraft, leaving their fates unknown, presumably deceased.
- While the comics version of the character has relations to the League of Assassins, she was still considered a helpful ally of The Bat-Family. Here she is portrayed as a straight-up villainess, though she does care about Heretic, even getting angry when Talia kills him, and seeks vengeance for it, killing Talia.