I’ve been cooking up conversion ideas a plenty. The sisters are fairly simple (if time-consuming) conversion idea at the moment. Use some trimmed-down chaos marine backpacks to replace their normal ones, file off the normal inquisition symbols, and cover their places with green stuffed skulls and chaos symbols.
The exorcists will be chaos rhinos with the turret hatch on back with a set of havoc launchers on it like an old-school chaos whirlwind tank.
I already have a Reaper mini in mind for converting into the priestess for the sisters.
The inquisitor is still up in the air, but I do have a spare chaos sorcerer mini I might use. The retinue will be some odd cobbled up things.
The guardsmen will be converted catachans most likely as I think they’ll fit best and the new plastics should be easy enough to work with. Add the odd mutation, maybe a robe here or there and a little greenstuff should play out fine.
The Black Knights are the ones I’ve been contemplating building the most because the GK models are just plain sweet. But they’re basically just blinged-up space marines with different weapons. Chaos marines are already pretty blinged-up as is. So I built a prototype with converted gauntlet-mounted storm bolter, halberd / pike thing, and a slimmed down backpack to help him stand out from normal chaos marines. I also added a smidge of greenstuff in the waistline to lengthen the torso a tad, though I think I may add a little more in the future. The rest will be in the paint job. Might do head swaps over to ones with plumes instead of the various horns as well. Have a look: