This is one of the very first miniatures I painted for the Beasts of Ruin, a Chaos Sorcerer. I don’t recall now what exactly inspired me, just that I had a very clear idea in my mind of what I wanted. What was key was that he looked sufficiently like a wizard as well as a space marine (thus the robes) and that it was clear that he had been wielding – and being wielded by – the forces of the Immaterium for a very long time. The latter meant plenty of mutations were vital but without him just ending up looking like a spawn – he had to appear viable; able to walk, talk and cast spells, not just gnash his many mouths and gibber.
The bird-like elements (the beaked head and wings) were chosen to make his allegiance to Tzeentch clear. I see him as an advisor to the Beasts’ commanders, roaming the galaxy in search of artefacts or lore that can increase his personal power but always returning to the warband to bargain for their aid whenever he needs to.