User blog comment:Vivaporius/AT Idea: Imperial Civil War/@comment-3341288-20120410231117/@comment-3398633-20120410234938

I understand what your saying, but this is the deal.

Lion rememb ers the glory of the Imperium, and he died before the Emperor was inerred on the Golden Throne. Plus, he hates the fact that the Emperor allowed the destruction of Caliban. Perhaps thinking the Empperor let the Imperium fall to pieces, Lion perhaps sees the Ecclesiarchy as the lesser of two evils.

Now, Gulliman saw the Imperium after the Emperor, but not what it would eventually turn into. Seeing the extreme differences in the Imperium compared to Ultramar, and being the "put humanity's interests first" dude, I would like to say he'd strike it out on his own to save mankind, and undo his father's failures.

Now for Abbaddon. Him killing Creed was just the beginning. The Chaos Gods got tierd of his failures, and upon securing the Cadian Gate, Magnus kills him for being an overall douche and complete failure in the name of Chaos. This sets it up for Magnus to take over, and become the new warmaster of Chaos. This is unless everybody wants Logar instead.