"Gone, gone the form of man! Rise the demon, Etrigan!!"
From the depths of hell comes a heroic demon come to undo the deeds of his past: Jason Blood, AKA Etrigan the Demon.
Sir Jason Blood was a veteran of the Third Crusade, but his religious zeal and anger won over him and he was driven mad with bloodlust, which culminated with him carrying out the massacre of Acre's 3000 captured Muslim prisoners. For his crimes, he was hung, but before he died, Death cursed him by binding his soul to that of a demon: Etrigan, now he walks the Earth seeking do undo the damage of his past.
Etrigan is the grandson of Trigon the Terrible, and thus the nephew of Raven, of the Teen Titans. Though they rarely ever met. If Jason Blood and Etrigan are split apart, not only does Jason grow old and wither, as Etrigan was the source of his immortality, but Etrigan falls prey to Trigon's influence, though it's not as powerful as when it happens to Raven.
For Etrigan's origin, I revamped his along with Shining Knight's, as they were both Arthurian knights, but since there's no historical record of King Arthur, I thought it'd make more sense to revamp them both as Crusaders. I also went for the traditional look that Etrigan had, with the exception of the eye pupils, which I made red.
Disclaimer: Etrigan belongs to DC Comics, and the legend - Jack "the King" Kirby!