The Fate Gryphons, or Sagodjur Fjorlag as they call themselves were at first a VIIth legion assault company left behind when the sons of Dorn were called back to Terra. Abandoned on the mountainous death world Nastrond Primus without any hope of help against the machinations of the Changer of Ways, they were at length compelled to recruit from the native populace, white-skinned elfish humans who lived in subterranean cities. Time passed and the ways of the Praetorian were forgot as the Nastrondite's morbid take on the Imperial truth was adopted through Nastrondite initiates.
Bad luck showered upon them in late M.32 when a Space Hulk appeared in orbit of the Nastrond system's sun. The disruption of the already unstable gravity broke open a hitherto unknown Necron Tomb. A decade of war did nothing to halt the Necron onslaught and as a last-ditch attempt to survive the Sagodjur Fjorlag relocated, along with as much of the populace as they could save, into the Space Hulk and committed Exterminatus on the planet. They then named the Hulk the Nastrond after the dead world and left it behind.
Now, long after their destruction in M.36 the Sagodjur Fjorlag are recognised as a 2nd Founding Chapter, but to call them a Chapter would be wrong; for they never heard the words of the Codex taught to them and so they never changed their ragged organization. They live in perpetual darkness. in a world of rust and blood forsaken-- in their eyes-- by the Emperor of man, who they treat as a deity along with Dorn their father. They are filled always with dismal thoughts. They are sadistic masters of escapology, delighting in nothing but the torture of their victims. They excel mostly in underhive-fighting and hulk-fighting but do so with what appears to be reckless abandon; for fear is nothing and death is less, for what do they care? Life means nothing to them anymore, be it their own or their allies.