Notes:

The Slaugth are a race of xenos whose bodies are composed of thousands of maggots who get high off consuming brains and create biomechanical attack penises with poisoned tips and disintegration rays.

I have not made that up, check the source and if 1d4chan's not good enough, Lexicanum says the exact same thing.

Not much is known about the Slaugth, due the great lengths that they and the Inquisition go to, to keep them hidden. One of the main things we know is that there technology is incredibly advance, possibly on par with the Necrons, and that it is mostly bio-mechanical in nature.

There is an unknown connection between the Rangda and the Slaugth, but what it is has been lost with all of the other information about the Rangdan Xenocides.

Oh, what's that?

Only one of the largest wars in the Imperium's history which almost resulted in it's complete destruction with only the Horus Heresy causing more damage.

It saw the complete destruction of the II and XI Legions, almost the complete eradication of the Dark Angels and the only reason the Imperium wasn't wiped out is because the Emperor unleashed the f------ Void Dragon upon the Rangda, which just managed to turn the tide in the Imperium's favour.

S---'s crazy yo.