By Imperial standards I don't think you could possibly be a more heretical traitor than telling the Emperor himself to go suck one...
Radical Inquistor's are debatable. They use chaos, and some puritan inquisitors call them heretics. The Book, "Eisenhorn" by Dan Abbet goes into great detail. I think its my favorite book from the black library
The guy is seriously a genius. To come up with some much wonderful lore, and keep it coherent is amazing. Anything he touches, is a amazing read. I just picked up Ravenor, and I want Bequin really bad as well when I am done
Well in the first place i believe that some Clegions didn't betray the IoM but were betryed by it and there are(were) several thousands space marines of "traitor" legions that were still loyal to the IoM or the carrion "lord" himself! What about assaulting him?
From my having read some of the HH novels most of the legions that defected did so because they agreed with Horus (Who wasn't the first to give into Chaos, mind you.) and several others followed simply out of loyalty to Horus as Warmaster and/or because he convinced them of his vision that THEY would be betrayed by the Emperor. Now, as I said there were countless members of the traitor legions that remained loyal and were killed for it. Istvaan V is where several of the Foundry Chapters of the LSM lost almost all of their men and where most of the remaining loyalist in the traitor legions were killed by virus bombing. This was planned by Horus and executed to help reduce the forced standing against him.
Well depends on the traitor official status in the imperium. If the the traitor is given a penitent quest when he is pronounced a traitor, then yes he can be forgiven. If there is not given a quest, then the only one that can absolve the traitor is the Emperor. In the afterlife. So if you are pronounced traitor by the imperium, the only mercy you can hope for is a quick death. I should be also be that just because some one from the imperium says that you are a traitor do not make is official. But they would probably kill you anyway. Just as if you were called a heretic. If you're wondering if member of the chaos legions can go back. Then no. They had their chance during the Horus Heresy. And now they are unforgivable traitors and heretics. To be tortured, maimed, burned and there ashes sent in to a sun, lest their remains sully the glorious imperium
There is one point worth considering, a story which seems to have gone unremarked upon. Written some years back, there was a tale by Ben Counter known as Daemonblood. Counter is known for having a less than positive view of Chaos as a beneficial force, but it's nevertheless an interesting subject given it has a Champion of Nurgle being convinced to repent by a Sororitas. Surprisingly, it does this without it feeling like a betrayal of either side. Apologies, i'd go into further detail but my copy was destroyed some years ago and I wouldn't want to misrepresent or misquote its pages.
