Moripatris var addthis_config = {"data_track_addressbar":true};

The Moripatris, known as the Mass of Doom, is a prayer uttered by Chaplains of the Blood Angels. When they discover that a Blood Angel is succumbing to the Black Rage, the Chaplain will utter the Moripatris, formally inducting the Space Marine into the Death Company.¹

Sources

• The Blood Angels Omnibus by James Swallow