Invisibles
The Invisibles were the elite bodyguard unit of the "Emperor of Mankind", the ruler of the planet that came to be known as Sixty-Three-Nineteen.[1a]
Their name was derived from an application of force field technology that gave them their main tactical advantage. They possessed a passive application of said technology that allowed them to bend light around themselves, making themselves practically invisible, even to Space Marine helmet sensors. However, the effect failed slightly when the user moved, and careful scanning using high-contrast viewing tools was able to reveal heat-haze type blemishes in the air. Their weaponry was also derived from force field technology, projected as invisible beams of mutilating force capable of penetrating power armour. Their weapons made a distinctive banging noise when discharged. For hand-to-hand combat they used long-bladed lances. Tall, physically fit men, they wore ornate silver armour and red silk mantles. They somewhat reminded Luna Wolves Captain Garviel Loken of the Custodian Guard.[1a]
The Invisibles were chiefly notorious for enacting the murder of Captain Hastur Sejanus and all his glory squad. They were defeated by the Luna Wolves and ordered to be decimated.[1b]
Their technology was noted to have been earmarked for reverse-engineering by the Mechanicum.[1c]
Sources