Eliphas was first present on the world of Kronus as part of the Shadow Crusade during the Horus Heresy, where he fought against the Ultramarines as the Chapter Master of the Ark of Testimony Chapter of the Word Bearers Traitor Legion. Eliphas sought to harness the power of the Warp in the construction of the mighty Templum Daemonarchia, however the full potential of the temple was never realised, as the Word Bearers on Kronus were recalled by Lorgar as the Shadow Crusade ended. He is presumed to have fought on Terra with the rest of his Legion, before retreating to the Eye of Terror when Warmaster Horus was defeated.