Lucian Calsius is a Lieutenant in the Ultramarines Chapter's 2nd Company and a veteran of the Indomitus Crusade, where he received his current rank. Due to being a relative newcomer to his Chapter, Calsius works hard to earn the respect of his Battle Brothers and has displayed bravery and wisdom in numerous battles. Besides the Indomitus Crusade, Calsius has also taken part in the Plague Wars and defeated an Ork attack on the Agri World Nova Thulium. His celebrated victory there, including personally killing the Warboss Guttrekk, proved to be the turning point that allowed the Imperium's forces to defeat an Ork invasion of the Realm of Ultramar's eastern flank.