Crimson Castellans

The Crimson Castellans were a Loyalist Space Marine Chapter of unknown origins and Founding who became embroiled in a civil war after a portion of their number turned to Chaos but were largely destroyed when the Tyranid Hive Fleet Jormungandr unexpectedly descended upon the world of Sephrax where they were battling their Renegade brethren. The Chapter homeworld of Vorl Secundus was subsequently abandoned and it is unknown whether the Chapter still exists in some form.

Chapter History
A portion of the Crimson Castellans was corrupted by Chaos and turned Renegade, becoming a piratical warband of Chaos Space Marines. The Loyalist Castellans hunted their corrupted brethren down on the Hive World of Sephrax. But while they were engaged in battle, the Tyranid Hive Fleet Jormungandr unexpectedly descended upon the world and forced both sides to lay down their animosity against one another to try and defend themselves against the swarms of bloodthirsty Tyranids that threatened to destroy the world and both groups of Astartes. However, the Hive Fleet;s sheer numbers soon overwhelmed all the combatants. The Crimson Castellans Chapter Master Sojai Antiro died in the bowels of the underhive of Hoventa Hive, declaring his defiance even as Tyranid Raveners encircled him and tore him to bloody shreds. The Renegade Crimson Castellans' leader, the self-styled pirate and "Arch-Commodore" Bloodspite, fled with the remainder of his forces to the lair he had established in an asteroid in orbit of Sephrax. But the asteroid and its defenders were ultimately swallowed by a Hive Ship of truly enormous size. The Crimson Castellans' Chapter homeworld of Vorl Secundis was abandoned shortly thereafter, and it is unknown whether any elements of the Chapter Loyalist or Renegade, may have survived the fury of Jormungandr.