Xa'ven was a member of the Salamanders during the Great Crusade and Horus Heresy. Commanding the 34th Company, Xa'ven led survivors of the Drop Site Massacre aboard a captured Luna Wolves ship and escaped alongside other figures such as the Iron Hands Legionnaire Bion Henricos. Later Xa'ven's ship encountered a White Scars vessel carrying chief Stormseer Targutai Yesugei, and the Salamanders captain informed him of the Horus Heresy. Xa'ven eventually agreed to help the Stormseer find his Primarch Jaghatai Khan, and they battled Word Bearers along the way. Xa'ven was shown to be as humane as his Primarch Vulkan, refusing to allow Yesugei to torture a captured Word Bearer for information.