Imperial Knights
Legio Mortis became one of the most notorious Titan Legions, directly supporting the Primarch Horus Lupercal before his treachery against the Emperor. Together with its Vassal Knight Houses that wore the same colors as the Legio, the Death Heads fought alongside the traitor forces. When the Horus Heresy began with the virus-bombing of Isstvan III, it was the Legio Mortis which made the landings to scour the corpse-packed hives for the last survivor.