Sebastion Blood became the host of an alien parasite known as the Brood Queen. Believing that being a Brood host was a gateway to spiritual enlightenment, Sebastian became the cult leader known as Brother Blood. He infected everyone who joined his cult with Brood eggs and made them his drones. Brother Blood was able to infect Terra-X and make her betray her friends on the X-Patrol.
Terra-X helped Brother Blood infect Niles Cable with a Brood egg. Niles was saved by Raveniya who used her soul-self to kill Brother Blood while Ex-Man used his telekinesis to help Niles safely use the techno-virus inside him to kill the Brood egg.
As host to the Brood Queen, Brother Blood has alien abilities. He is superhumanly strong and can sprout claws from his fingertips or spines from his body. He can infect humans with Brood eggs with his claws and mentally control anyone who has a Brood egg inside them. Brother Blood can also shapeshift into a monstrous form that is a hybrid of both Brood and human.