
I always love the fluffy stuff, so I will try and keep your theme going, but on that note here are some things I think you might find improve it a bit. (really sorry for the long post)
1. trim down on the cultist blob for a few extra points, try exchanging your murder sword for an axe of blind fury, because while it is not instant death and strength 10 versus that "special someone" it is strength 7 on the charge with more attacks then most characters can honestly handle, but if you don't like the daemon weapon rule then I can see keeping the sword.
2. your troops need a delivery system, so I think rhinos would give them a lot of the speed they need.
3. and while the mark of slaanesh is great on possessed marines, I just can't get possessed to work as they can only move 6 inches and then run, so they are hard to use properly, so consider maybe mixing them up to create some chaos spawn who are really fast, force shots, and can take on most units in
CC.
4. the loadout on the
CSM I feel like the missle launcher will just slow you down as you will want to move,and that single snapshot just isn't that great, so try maybe flamer,and plasma or flamer melta.
5. this looks like a fun list, so I won't hit you with the obligatory "wheres your anti air" because at 1k points I'd like to believe people don't use flyers that heavily,but it happens way more than it should, so consider a reaper auto cannon in your terminator unit, or creating a havoc squad with auto cannons to help.
6. if you continue to like the chaos vibe, but you don't know what models to spend your hard earned cash on.
consider some elite options from your favorite chaos god, and go from there.
and again sorry for the long post