User blog comment:Abyssal Horror/Idea: Darkness Rising (DR)/@comment-3562230-20120420035136/@comment-3562230-20120427165331

I don't know. For me, I think Magnus would turn back to the Imperium based on his conduct in the book "A Thousand Sons." Besides, since trickery is something all followers of Tzeentch specialize in, it seems natural that Magnus would betray Tzeentch.

Part of the problem is that in most of the codexes and early literature every chaos god was given his own space marine legion to serve him so the thousand sons have been considered as loyal to Tzeentch and they were indeed portrayed as loyal.

In the horus heresy novel, "A Thousand Sons" quite a different picture is given. Really, Magnus and Ahriman are slaves to the Legion, both will sacrifice anything to save the Legion. (Magnus' pact with Tzeentch to stop the flesh change and Ahriman's Rubric) So, I would think Magnus doesn't really care about Tzeentch. The instant he can remake his Legion and undo the wrongs he did to the Emperor, he will do so right away.