All in all it really didn't take much work to get him to this stage, in fact it only took two backpacks, a plasma pistol arm, a Death Guard arm, Chaos shoulderpad, a resin pouch (from Maxmini), some Green Stuff and a bit of patience.
Both arms took some sculpting and gap filling, but most of the work went into this gut. Though slightly gruesome, it's grimdark 40K afterall, I really do enjoy sculpting organic areas like this. There's just something about taking a random lump of putty and making it fit in with the rest of a mini.
For this mini I used a combination of Masq-Mini's Tubetool (link) for the tubing on his back and in the gut, and the saving grace for any amateur sculptor - clay shapers. I got my first set from Heresy Miniatures (link) many years ago and have been using them ever since on virtually every sculpting project since. Tools like this aren't cheap, but they last for a very long time and will greatly help both for texture and smoothening of putty.
One thing is certain though, this fellow turned out huge. Below there's a size comparisson with him, a true scale Techmarine and one of my old Relictors (based on 3rd edition Tigerius).
This coming week I'll take care off the final detailing, afterwhich the painting can begin. Rather looking forward to tackling the Purge colourscheme again, should be interesting to somehow combined it with all the flesh on this miniature.