Warhammer 40k: I Became Mortarion

At the end of the Terran Unification Wars, the God-Emperor's offspring was cast across the galaxy by a Warp storm. The Emperor's Great Crusade unfolded across the galaxy under the watchful eyes of the Four Gods, foreshadowing the future of humanity. For unknown reasons, an alien soul arrived in Warhammer, becoming the Clown Primarch, Mortarion.