Saul came into contact with Apocalypse in the 12th century and was a member of the High Lords who were calling themselves the Externals. He tried to enter a crashed Celestial spaceship but was beaten by Apocalypse. He was killed centuries later by fellow External Selene when she drained the life force from him and most of the Externals, showing that they truly weren't immortal.
Channel biological plasma energy into explosive force discharges and levitation. He was also immortal, at least until he died. As a minor power, he was fireproof.