The Bloodtide began as billions of nanotech robots. According to the Bloodtide itself, they were created long before the rise of the Imperium. Prior to then, each tiny robot had a spark of will, but during their long slumber those "sparks" merged into a single consciousness.
They functioned by entering their victims' bloodstreams and then causing their blood to burst forth. The effect of this, performed on millions of individuals simultaneously, was to drown whole worlds in blood. However, the Bloodtide was bested and they were imprisoned beneath the earth to sleep for eternity and it became known only as a legend to the rest of the galaxy. This sleep would be disturbed by Voldorious who bound the ancient weapon to his will. However, the Bloodtide did not desire to be bound to a life of servitude but its creation prevented it from ending its own existence.[1b]
The Bloodtide was capable of taking a silver humanoid form with a luminous shape with a disturbingly serene expression on its face with deep, solid, blood red eyes. The body rippled and swirled and was immune to most weapons fire.[1b] Its silvery figure displayed neither male nor female features nor did it show a young or old face. However, an intelligence was capable of being gleaned from the eyes of this construct.[1b]
Having unleashed the weapon once before, Voldorius attempted to master the Bloodtide again, during his conquest of Quintus. The Bloodtide formed before the eyes of a detachment from the Raven Guard Chapter sent to liberate the world. The Astartes' weapon fire did not harm the entity, which reacted by releasing microscopic robots which felled several of them, including Brothers Meleriex and Shahan. Even their enhanced physiology did not prevent the blood from flowing from their bodies.[1b]
However, the Bloodtide determined that the Raven Guard were enemies of Voldorious and attempted to communicate with Sergeant Kholka, asking to be destroyed rather than be abused by Voldorius.[1b] The Bloodtide revealed that it was vulnerable to fire, and also that a portion of itself had been taken to infect a human woman whom Voldorius intended to use to spread the Bloodtide.[1b]
When Kor'sarro Khan of the White Scars confronted the Daemon Prince, he faced an obstacle of raw Bloodtide, which needed to be burnt in order to clear his way.[1c] Voldorius was eventually destroyed, and the Bloodtide presence on Quintus was destroyed, although the human woman disappeared along with the Raven Guard.[Needs Citation]
Later, in 876.M41, the Bloodtide would return under the command of the Bloodthirster Ka'jagga'nath on the world of Van Horne. This time, it was only halted by the efforts of the Grey Knights, who slaughtered the remaining uncorrupted Sisters of Battle of the Order of the Ebon Chalice and used their innocent blood to form a talisman of purity, ending the rampage of the Bloodtide and Ka'jagga'nath.
- 1: Hunt for Voldorius (Novel) by Andy Hoare,
- 2: Codex: Space Marines (5th Edition), pg. 42
- 3: Codex: Grey Knights (5th Edition), pg. 15