Sanguinius

Sanguinius is primarch of the Blood Angels, the winged angel of Baal who stood on the walls of Terra when no one else could hold the Eternity Gate. His sons still drink a curse that began in his blood.

He fought through Signus, refused Horus's offer of ascension, and died on the Vengeful Spirit before the Emperor arrived. The death was not a surprise to him. He walked into it anyway.

Baal keeps his tomb as if he might wake. Dante wears his death-mask into every war that matters. The Flaw is the part of him that did not stay dead. The Sanguinor walks in his place when the Chapter needs a miracle that is not Dante.