I'm also reasonably proud of the Tzeentch mark on the back. There was a lot of empty space on the back of the Destroyer body; at best it was kind of textured with the drybrushing and washing. At worst it was kind of 'bleh.' So, I pencilled in the symbol, then painted it, and BAM! Emeril-style, it looks better.
The base is a standard 60mm round, and the lava-bits are Squadron Green Putty. Gotta love that stuff for adding texture to bases. Then it's painted, and some GF9 ash waste flcok thrown into it when it's drying.