A venerable battle-seer and a member of the Corvidae, he joined with Ahriman's party to reclaim the shards of Magnus during the Horus Heresy. However after seeing a vision of what will become of Magnus and the Thousand Sons in the future, he became determined to aid the Imperial party hunting the shards led by Dio Promus and was willingly captured by them on Kamiti Sona. On Aghoru, Menkaura sealed a shard of Magnus into the captive Lemuel Gaumon. He further accompanied Promus' force to Nikaea, where he became trapped in the Crystal Labyrinth summoned by the rampaging possessed Gaumon. The visions he experienced within the Crystal Labyrinth drove him insane and he clawed out both of his eyes, rejoining Ahriman's cabal afterwards.
By the post-Heresy period, Menkaura had become a Daemonic oracle to Ahriman.