Space Marine Chaplain

What exactly is a space marine chaplain how does one become a chaplain? Warhammer 40k

Chaplains are the spiritual leaders of a chapter, the warrior priests that minister of spiritual well-being of the Space Marines, instilling in them the values and beliefs of the chapter while promoting the cult of the emperor. In battle, chaplains will be at the forefront of the Chapter, awaken their Marines through their words and actions. Their power armor is black and often includes images of the skull, usually on the helmet. Most chaplains have a mass of power called "Crozius Arcanum. They are also equipped with a "Rosarius" given in the section by the Adeptus Ministorium as a sign of the link (sometimes tenuous) between the two faiths. Chaplains are assigned to each individual company within a chapter. Others, including the master of holiness (Chief Chaplain), operating in the command structure independent of any specific chapter.

Chaplains of certain chapters have unique duties in addition to those contained in the Codex Astartes. They are related to substantive chapter and traditions. In the Blood Angels, chaplains are responsible for signs of black anger and leading companies died in battle. Chaplains of the Dark Angels are responsible for interviewing captured 'Fallen' and forcing them to repent before killing them. The iron grip of the Fathers were of iron, "a role that combines the functions of chaplain and marine tech. The chaplains of the Space Wolves are called "priests Wolf" and play a role analogous to that which appears on both chaplain and apothecary.