Sanguinius

Sanguinius, also known as "The Warmaster" and the "Crimson Angel," is the Primarch of the Crimson Legion (formerly known as the Blood Angels) of Space Marines. He was nearly slain by the Emperor of Mankind during the Battle of Terra on his flagship known as the Red Tear, however he also mortally wounded the Emperor, thus causing him to be interned on the Golden Throne. He also killed Horus Lupercal, Primarch of the Luna Wolves, during this fight. His current status is unknown, however he was last recorded entering the Eye of Terror for unknown reasons.