cheesetruncheon: We'll be back, stronger. We always are.
Not really. You have already adapted as much as you can with Ork DNA. On the other hand Orks grow quicker than you can eat them while at the same time fightin' keeps making them stronger. When the nids are beaten back from Octavius (and they will be) the Orks that will come out of there will be unbelieveable.
Damnation: Indeed, but not all four Chaos gods would elect him their champion, Khorne would most likely be strongly against the idea, based solely on Ahriman being a sorcerer. Slaanesh might not wish him to be due to the Thousand Sons being dust and all that, same for Nurgle.
Which is why you end up with Abaddon.
Khairn is in charge = Get the boys together. ALL OF EM. We attack Cadia full frontal. I want their guns blocked with the gibblets of dead Chaos Marines.
Ahriman = We sit, we wait, we plot.
Fabius Bile = I couldn't care less, bring me more test subjects
Lucius = Dude I would so hit that.