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 are unwitting experts at bioengineering who thrive on war, meaning whoever ultimately wins will emerge much stronger than ever before (though hopefully if the Tyranids win they will be overspecialized ork killers and be weak to other threats and fighting styles). The conflict has predictably devolved into a massive meat grinder, where neither side has a clear shot at winning, and both are fucking loving it.
Never mind on the Eldar part, they're currently trying to clean up Kryptman's mess by bio-purging the front line and the 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. After arriving there and killing a mawloc from the inside out (eat your heart out, Alien), he's managed to take command of the Octarian orks.
With so much carnage and destruction going on, it was bound to attract the attention of the Ruinous Powers. In particular, a Khornate warband called the Skullhunt of Vodha Bloodprice attack the system, declaring a Blood Crusade. And their results are... mediocre, to say the least. In the CSM 8th ed. Codex, it says the khornates were able to get "over eight thousand skulls are offered to the Blood God, the smallest of which is the size of a boulder" and that was enough to make Vodha Bloodprice ascend to Daemonhood. Which sounds too weak to be true. Sure, skulls the size of boulders are nice and all, but considering the amount of orks and tyranids around Octarius, just 8,000 skulls is too damn little. We can get that amount of deaths by a relatively safe trip to the Warp, or a very successful imperial guard campaign. But Khornates fighting Orks and tyranids, two of the most bloodthirsty and warmongering, not to mention numerous, species in the galaxy, all this confined on a single planet? It just screams lazy. Khorne must be becoming old if he grants daemonhood for such a half-assed job, or they were only offering Khorne the skulls of the really big stuff they killed, Warboss and Carnifex size or above, not the countless Boys, Gaunts or Warriors they slaughter. Only the best for Khorne: after all, which would the Blood God appreciate more, 1000 regular Ork skulls or the skull of an Ork big enough to give a Bloodthirster pause? Anyway, the Blood Crusade probably had to retreat fast due to the massive opposition and being sandwiched by the orks and nids, and the fact that the Indomitus Crusade started, so there were fresher pastures to drown in blood. Said Khornate Warlord did kill a Hierophant Bio-Titan with the Axe of an Ork though, which is incredibly impressive in its own right, and if people like M'kar can get Daemon Princehood, it's quite clear anyone can.
Since then, the worst-case scenario has gotten even worse, as both Orks and Tyranids have begun breaking away from Octarius to attack any world they can reach, thus making Kryptmann's whole plan entirely pointless.