Octarius War

It's this. And it's happening 24/7 in the Octarius system.

The Octarius War is the most hilarious and fail venture the Imperium of Man has ever made. And believe us, that is no small feat.

The Imperial Guard were having their asses handed to them by the Orks on the planet Ghorala in the Octarius system. Former Lord Inquisitor Kryptman, leading expert on the Tyranids and prolific bastard, decided that the best solution would be to sic a recently captured swarm of Tyranids on the Orks, let the two fight it out, and mop up the remaining survivors with the IG. The obvious flaw in his plan of course is that both Nids and Orks thrive on war, being unintentional experts at biological warfare, meaning the survivor would emerge much stronger than ever before. The conflict has currently devolved into a massive meat grinder and both races are fucking loving it.

This tale is notable for being one of the few bits of fluff in the Nid 'dex where they don't get their arses handed to them by space communists, space elves or fucking smurfs

Never mind on the Eldar part, they're currently trying to clean up Kryptman's mess by bio-purging the front line and worlds around it. Unfortunately, they missed the Overfiend of Octarius, who just managed to loot an Avatar of Khaine...fucccckkkkk.

Oh, and Ghazghkull himself is on his way there too so he can call up more boyz for Da Great WAAAAGH!!!! Score one for the Orks, it looks like