Jason Blood

During the Magistrate's takeover of Gotham City, Jason was held captive in one of their detention facilities due to his alliance with "masks". He found himself as part of Spoiler's gang, and he eventually helped with the insurrection and breakout of the prisoners.

Years later, as Merlin began trying to bring the forces of magic under Earth's control, one of his first tasks was to separate Jason from the demon inside him, Etrigan. When they were apart, Merlin let the world believe Blood was dead, while instead he recruited him to his army. Jason became Merlin's Blood Knight, and joined him in his war on the supernatural, even against his own former allies in the Justice League Dark.