History of Blood
The first Brother Blood was the high priest of the Baltic country of Zandia who refused to supply recruits for Pope Innocent's Fourth Crusade in 1202. During the ensuing battle, the high priest gained the Cloak of Christ, allegedly worn at the Last Supper, but now corrupted with evil. Wearing the cloak, the priest led his knights to victory. He then bathed in his enemies' blood, which gave him great strength and virtual immortality. The priest declared himself Brother Blood and closed Zandia to all strangers, except those who will join his church and plege all they have to the church.
He ruled for 60 years, fathering a son who killed him at age 100. So began the terrible Curse of Blood, whereby each son of Zandia's ruler slew his father, bathed in the Bloodpit, then ruled in his place.
This gruesome pattern of events has recently continued as yet another son has killed his father. However, this particular 14-year-old lacks the training of his predecessors. Instead, his ultimate goal is world domination using his church's might. The Outsiders and Teen Titans, though, stand in his way. He tried to wed Raven, as a part of a prophecy to bring Trigon to Earth. He was stopped. He later tried to take over the world again, starting with the Teen Titans, by stealing Kid Eternity's powers. He raised the dead Titans, planning to kill the living ones. He was stopped by Kid Eternity, who brought back the former Brother Blood's, who tore Sebastian to shreds.
He grew up in Hell, having been tortured for so many years even he can't recall how long. He believes that being there is all part of Trigon's plan. Then one day the magical binds holding him, break, setting him free, turns out all the prisoners in hell have been set free. He sets out to find Trigon, to be his loyal soldier, but is attacked by a demon with tiny mouths on his fingers, who starts drinking his blood. Brother Blood then gains the upper hand and bites back, finds out the demon has a healing factor, and rips his arms off. He then finds Kid Eternity and tells him to look at his killer. Kid Eternity turns into Aquagirl getting a few punches in before his power runs out. Brother Blood comments on Eternity's power loss, then bites him, teleporting them to Titans Tower. Brother Blood then bites Misfit, uses her powers to teleport, then bites Wonder Girl's leg, leeching her powers. Brother blood then bites Red Devil, but says his blood is tainted by Neron. He then uses Red Devil's power to make a portal. He then starts searching for someone to be his 'mother'.
First appearing in an ominous dream of Beast Boy post Flashpoint, the helmet he is seen wearing suggests that he is Sebastian Blood. He next appears emerging from a pool of blood, talking to three women who tell him how to open a portal to the Red using the blood of the Ravagers and that one of them is the key. Unlike the previous presentation of Sebastian, he appears rather irreverent and refers to his fleshless acolytes as 'morons' as he dispatches them to capture the targets. When they resist his acolytes, he shows up and heals Lightning, taking control of her as he touches her blood. He proceeds to drain blood from Thunder as the others are captured. Back at the sanctuary of the Church of Blood, he recognizes Beast Boy from a dream. He tries to charm Terra before battling the crimson changeling. Lighting's leap into the portal causes it to blow up and bury him under rubble though he still seems to be alive.
Powers and Abilities
Brother Blood is able to steal powers vampirically. He leads a cult of devoted followers. These followers in the New 52 appear to be a bunch of mindless individuals who no longer have skin. His powers are different as well. He heals Lightning and hypnotizes her by touching her blood and drains blood from Thunder. He also seems to naturally possess super strength and durability.
Brother Blood appears in the Teen Titans TV show as the headmaster of the H.I.V.E. Academy. He is shown to have a strong interest in Cyborgs robotic body and later in the show he becomes half robot.
Sebastian Blood first appears in Season 2, Episode 2 of Arrow: "Identity." Kevin Alejandro plays Blood, an Alderman claiming to be a helpful force for The Glades.