Oxiods Xenocide

The Oxiod Xenocide was an Imperial xenocidal campaign carried out by the vengeful Emperor's Reapers Space Marine Chapter against the now-extinct xenos race known as the Oxiod.

Background
In 175.M33, the Empower's Reapers discovered a undiscovered human colony from the Dark Age of Technology that had fallen victim to a xenos race known as the Oxiods. These vile xenos had enslaved the human population for millennia and relegated their human captives as a slave work force and food supply. Enraged by the mere thought of any human being subjected to the whims of alien filth, enraged the Emperor's Reapers with righteous wrath, and the Chapter sallied forth to kill every last one of the xenos present. Over the course of an 11-year long campaign, the Chapter trained the natives in the art of war as the Reapers helped them fight against their oppressors and liberated their planet. Their world was then brought into the fold of the Imperium as members of the Adeptus Mechanicus scoured the newly inducted world for STC fragments. The Reapers claimed their due, since that era has used the world, named Helias, as one of the Chapter's primary recruiting worlds.