'''Callion Zaven{{PAGENAME}}''' was a member of the [[Emperor's Children]] during the [[Great Crusade]] and [[Horus Heresy]] who went on to join the [[Knights-Errant]].

'''Callion Zaven''' was born on [[Terra]] and inducted into the [[Emperor's Children|III Legion]] during the [[Great Crusade]], before the discovery of their [[primarch]] [[Fulgrim]]. In battle on [[Jupiter]], a [[Vapour-Wraith]] warrior struck him in the heart with a hewclaw and he was inducted into the [[Crusader Host]] as the rest of the [[Space Marine Legion|Legion]] had moved on by the time he recovered. He kept the hewclaw that wounded him, fashioning it into a duelling sword.{{fnFn|1a}}

Zaven remained loyal to the [[Emperor]] during the Heresy and joined [[Malcador (Character)|Malcador]]'s [[Knights-Errant]].{{fn|1}} In 017008.[[M31]] he accompanied [[Nathaniel Garro]] and [[Tylos Rubio]] on [[Pale Stars campaign (Horus Heresy)#Conclave of Optera|a mission ]] to [[the Pale Stars]] where they recruited the [[Nemean|Nemean Reaver]].{{fnFn|2}} Later he was part of the mission to infiltrate the ''[[Vengeful Spirit]]'', during which he was seriously wounded fighting [[Sons of Horus]]. Despite the efforts of [[Apothecary]] [[Altan Nohai]], Zaven died of his wounds.{{Fn|1b}}