A Chaplain is the spiritual leader of a Space Marine Chapter, a warrior-priest who tends the souls and beliefs of his transhuman brothers. Clad in black armour and bearing a skull-faced helm, he is the keeper of the Chapter's cult, its rituals, and its reverence for the Emperor and the primarch from whose gene-line the brotherhood descends.
In battle, the Chaplain is a figure of terrifying inspiration. Wielding his sacred crozius, he strides at the forefront of the assault, roaring litanies of hate and courage that drive his brothers to feats of superhuman valour. His presence steadies wavering hearts and turns grim warriors into instruments of righteous fury, for few things fortify an Astartes like the words of one who guards his very soul.
Away from the fighting, the Chaplain officiates the solemn rites that mark a warrior's life: the initiation of recruits, the honouring of the fallen, and the observances that bind a Space Marine Chapter into a single devoted brotherhood. He guards against doubt and heresy within the ranks, ensuring the purity of belief that keeps his brethren steadfast. In this way the Chaplains of the Space Marines preserve not only the bodies of their orders but the fierce faith that gives their endless war its meaning.