December Graystone was an assassin and a mage. Due to his ability to use blood, December once went by the codename Blood Mage, but abandoned it.
Becoming an assassin, due to his talents as a blood mage, December Graystone took up the title Blood Mage and entered the League of Assassins. Being trained by Bronze Tiger, December became a good friend of Jason Todd. Shortly after Todd left the League, December abandoneed the title Blood Mage.
Refusing to join Leviathan, December's life returned to relative normalcy after the Battle of Gotham City. Along with Bronze Tiger, December helped bring back Jason Todd to the League to fight the Untitled.