Cool fukken picture and all, but I find it weird that what is almost certainly a member of the Legion of the Damned is walking around with Chaos iconography.
I got the idea from an old wh40k fanfiction that was quite popular like Rise of the Tau. It came about 3rd-4th edition when a lot wasn't known about the Legion of the damned. The fanon was they used the powers of chaos against itself with the guidance of the Emperor.