What you'll need:
- Sorcerer parts from Chaos Lord/Sorcerer in terminator armor
- Black Reach Terminator Sergeant body
- Chaos Spawn bits
Specifically in this case, the Black Reach Terminator Sergeant is in the middle, with the imperial doodad removed. The spawn bits are off to the left and the chaos termie lord/sorc bits I used are off to the right.
First off, cutt off the veteran symbol on the sergeant's' left knee and the purity seal from his right leg. You'll need to mask those areas a little, so choose bits to go there. In my case I picked the little arrow with skull to cover the knee and just cut the leg to be not too unsightly.
In an act of kindness, the front of the sorcerer termie armor fits perfectly into the black reach termie armor, so no conversion needed there. The chain loin cloth thing needed a bit of carving down on the inside to fit halfway decently in front of the leather straps that were there, and the skull from the belt buckle needed to be shaved off. Using different bits to chaos-it-up I don't see why you couldn't leave those as they were.
The big challenge here is that the Lord/Sorcerer box contains two left arm shoulder pads but only one right arm should pad, which the Lord got. To compensate for the missing shoulder pad, we'll be using spawn bits to create a warped and mutated (a.k.a. "The Chaos Crutch") right arm holding that book bit. Just for fun, I decided to add these very useful looking wings as well.
You can see here that I carved the spawn spikes down shorter so they would add some bulk to that area while not impeding on the wings too much. I used styrene glue to mush everything together, and then reshaped the joins to look better. Before I paint I will putty some to smooth transitions.
The wings are pinned into the back corners of the square on top of the termie armor. Save yourself heartache and pin things like this. PIN EVERYTHING. REGRET NOTHING. Especially in plastic, it takes almost no effort.
The book was adhered with a tiny spot of super glue in the hand and tentacle to keep it in place.
So there you have it. Other than a bad case of "loyalist legs" he's perfectly passable.