Taking an interest in the Inquisitor Ramius Stele, Malfallax started influencing Stele's desire to study the Warp. Eventually, Stele tried a containment spell on Orilan, but mispronounced a single syllable, allowing Malfallax to begin manifesting. This in turn caused rampant mutations and merging of flesh and metal across the planet, and the Adeptus Terra dispatched the Blood Angels under Erasmus Tycho to deal with the threat. Stele and his bodyguard Marain managed to escape, but Malfallax followed, eventually convincing Stele to murder Marain and devote himself to Chaos. Malfallax allowed Stele to appear to defeat him, saving Captain Tycho and earning a blood debt from the Blood Angels.
Years later, Malfallax and Stele entered into a bargain with Warmaster Garand of the Word Bearers to turn the Blood Angels to Chaos using Arkio as a false messiah. When Arkio was killed by his brother Rafen, Stele summoned Malfallax, intending to have the daemon possess his slave Ulan. Instead, Malfallax betrayed Stele and possessed him, fully manifesting as a Lord of Change. Malfallax attempted to cause the Blood Angels to succumb to the Black Rage, but was in turn banished by Rafen using the Spear of Telesto.
Following the failure of Fabius Bile's plan to make a clone of the Emperor of Mankind, Malfallax partially manifested on his Crone World and offered him an alliance against the Blood Angels, but Bile refused.
- 1: Blood Debt (Short Story) by James Swallow
- 2: Deus Sanguinius (Novel) by James Swallow
- 3: Black Tide (Novel) by James Swallow, Epilogue