Eliphas the Inheritor is a Chaos Space Marine Dark Apostle from the Word Bearers Legion who seeks the favour of Chaos Undivided (Worshiping all four of the Chaos Gods equally). He leads the Chaos forces on Kronus during the Dark Crusade campaign and leads the Word Bearers from the Deimos Peninsula, seeking to redeem the honour of the chapter after their defeat during the Horus Heresy. In game play when players have all the wargear available to him, Eliphas turns into a Daemon Prince for the remainder of the game as his final upgrade, although strangely enough his voice does not change during dialogue while he is a Daemon Prince, although his in-game voice acknowledgements do.
If the forces of Chaos win the Dark Crusade, Kronus transforms into a Daemon World and most of the population of Kronus become Chaos Worshipers or are sacrificed to the Chaos Gods. Eliphas becomes a Daemon favoured by all for of the Chaos Gods as well as Abaddon the Despoiler and Lorgar, the Primarch of the Word Bearers. Eliphas rules over this new Daemon World and uses it as a bastion of Chaos power so he can launch further attacks against the Imperium of Man. He also retrieves the skull of Lord Crull, the Chaos Lord from Dawn of War: Winter Assault and earns the favour of Khorne, the Blood God.
When either the Blood Ravens assault the Deimos Peninsula, or the Word Bearers attack the Space Marines, Eliphas comments during the battle that the Blood Ravens could be a loyalist splinter of a Traitor Legion. Should Eliphas defeat the Blood Ravens, he earns Abaddon's favour.
If the Chaos army is defeated and the Deimos Peninsula taken by another army, Eliphas is shown conversing and shouting at an unknown Daemon Prince who appears inside a collapsing Warp Portal, a Daemon Prince who has come to punish him for his failure.
In game play Eliphas in his Daemon Prince form is one of the most powerful units in the campaign.