Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

To me it makes most sense for it to be:

Chaos Rising: Neutral. Force Commander and Thaddeus are sent to the Eye of Terror for using Chaotic weaponry. Avitus is the traitor and Tarkus kills him. Tarkus isn't tainted in anyway.
Retribution: Space Marine ending mixed with Imperial Guard.