Last Stand of the Sabertooth

The Last Stand of the Sabertooth was the name of an extermination campaign conducted by the 4th ' Sabertooth ' Host of the Astral Warriors Chapter against elements of surviving xenos, known as the Vya, following the Vya Empire Extermination. But just as the Astral Warriors tracked down the remaining elements of the hostile xenos and prepared to strike a killing blow, they were attacked from an unexpected quarter - they were attacked by the infamous Blood Jaws Chaos Warband. In the ensuing battle, the majority of the 4th Host were massacred by the blood-frenzied Heretic Astartes. The few that managed to survive the initial slaughter, were ruthlessly hunted down by the bloody-handed berserkers and utterly annihilated. To this day, the Astral Warriors revile this hated Chaos Warband, and have been known to abruptly leave an active warzone should word reach them of any rumoured sighting of their most hated foes.

History
After the extermination campaign, the 4th Host stayed behind to deal with the surviving Vya that were hiding from the wrath of the Imperium. But just when the Astral Warriors were about to finish off the last Vya survivors, the Chaos Warband known as the Blood Jaws attacked and killed 240 marines out of the 270 composing what was left of the host after the Vya campaign. Both the xeno race and the 4th Host were utterly annihilated, with the 30 marines surviving the initial surprise attack being hunted down by the Blood Jaws and unable to reach out to another Host. Filled with grief and rage, the Astral Warriors reserve a fury against the traitor Marines.