I'm not the best painter, but I do pride myself on conversions. Some of the extras I put on it with some bits from my box:
-Used the ccw as medusa tendrils (more freaky)
-Empire great cannon for the battle cannon (now all I need is someone to "lash" people into nice tight clusters) >:)
-Extended the weapons to look more like arms with weapons instead of weapons sprouting from the shoulders.
-Used original battle cannon as the TL heavy flamer (hot glue to look like it is dripping napalm and painted cotton for oily smoke)
-Added a couple IG autocannons to make the reaper AC look more scary.
-Chaos dwarf cannon gun shield for the front plate
-Lots of hobby chain super glued onto various places
Morale of the story: use your imagination and be creative with your models. Anything can be used to make it more interesting.