The Crow Spirits are grim, cold killers who seem bent not on piracy but the selective annihilation of humanity within the Koronus Expanse. Clad in glittering armor that shines as if filled with moonlight, they make no sound in battle and are led by witches robed in pale tatters with tall helms of gleaming bone. Their ships are like pale dead things driven by a cold and broken will. Their tattered ethereal sails propel them from the depths of the void to strike at ships, colonies, and stations in the Foundling Worlds, Accursed Demesne, and Unbeholden Reaches. Cloaked and unseen until it is too late, the Crow Spirits are borne on a storm within the warp and real space that boils and screams with ethereal voices. They destroy and kill with a cold precision---and then leave, taking no prizes. Who leads these mysterious Corsairs and what their purpose is remains unknown, but some have speculated that they are guarding something, or keeping something from being discovered. At least one Inquisitor of the Ordo Xenos believes that they have some tie to a notorious Eldar Corsair in the Calixis Sector---Ulthyr Ellarion.