Void Stalkers

The Void Stalkers are a Chaos Warband that inhabit the world of Malleum. From their main fortress of Basilica Noctis, and under the leadership of Lord Diablo the Defiler, the Void Stalkers launch multiple raids throughout the Materium.

History
The Void Stalkers were once a loyalist Astartes Chapter called Angels Vigilant. The Angels Vigilant was a Blood Angels Successor Chapter originating from the planet Mavros. A decade to 236.M39, the Chapter was nearly eradicated. The daemon Baleros reached out to the Angels Vigilant via the Chapter's Chief Librarian, Elymas. Baleros promised salvation for the Angels Vigilant, in exchange for the Chapter turning to Chaos. Hadrian Nero, Chapter Master of the Angels Vigilant, agreed to the terms. Over the next decade, the Chapter began converting the denizens of their homeworld into Chaos Cultists. The Imperium caught wind of the Angels Vigilant's suspicious activity and sent the Iron Spears to subjugate the Chapter. Upon arriving at Mavros, the Iron Spears discovered the true extent of the Angels Vigilant's treachery. The Iron Spears declared Exterminatus upon the planet and eradicated much of the Angels Vigilant Chapter.

Several companies of the Angels Vigilant managed to escape persecution and renamed themselves the Void Stalkers. Baleros lead the newly christened Void Stalkers to the planet Malleum within the Eye of Terror. Their the Warband constructed the mighty fortress of Basilica Noctis. Hadrian Nero, now named Tenebrae Diablo, conducted numerous small raids into the Materium to acquire slaves to replenish their numbers.