So, here are the beginning phases of my recent Chaos Space Marines project: my Tzeentchian Warband, The Watchers Of Ophios. This is not a finished group shot (hence me labelling it a WIP), but it gives an idea of how the units may look against each other. Over the coming weeks, I intend to add some Havocs (built but not painted), some Raptors (ditto), some counts-as Thousand Sons, fashioned from the bolter-wielding Chosen from the Dark Vengeance kit; another Rhino (for the aforementioned Rubricae) and a Heldrake (hurrah!). This isn't designed to be a competitive force, and I won't even play them on their own, really. I have a much larger Nurgle force, with smatterings of Slaaneshi and Khornate units thrown in, forming a Chaotic Coalition of sorts, from which I will be able to draw whatever units I need for a particular battle. This Warband is more for fluff purposes, and because I like the paint scheme I stumbled upon.
These are my Chaos Marines, fashioned from regular CSMs, but using the Warp Talon heads from the dual kit Raptor box.
Here is my Chaos Sorceror, Orestes Agammemnon, who will lead this troupe of ne'er-do-wells into battle. As you can see, he's just a modified Chaos Lord from the Dark Vengeance box, with his head swapped out for one of the more Tzeentch-y ones from the CSM kit, and his arm hacked off and replaced with a freaky fireburst one from the Possessed kit.
All of my Cultists in this Warband are quite heavily modified, since I have so many sets of Cultists from a number of DV boxes. The Champion, for instance, features a Chaotic head (from Maxmini? Kromlech? One of those...) combined with the clawed hand from the other Cultist Champion that comes in the boxset, and the right arm from a Flamer Of Tzeentch. I've also used some parts from the Plaguebearer kit (which I have found look really different if you use an unfamiliar palette for them - ie, steering away from greens and browns) and the Empire Flagellants. The latter of these two kits is fantastic for combining with 40K miniatures.
And last, but not least, here is my Hellbrute: 'The Inconstant' (as named by my good friend, Himn). I hacked off his Multi-Melta and gave him a twin-linked Lascannon (fashioned out of two regular Lascannons) for a bit of variety and long-range capability in my army. I already have two Nurglite Helbrutes with Multi-Meltas, so this just offers something different (and possibly more reliable... I have lost count of the amount of times my hellbrutes have been destroyed after rolling 1's and 2's to hit with their Big Guns...)