For the initial color blocks I painted all the flesh areas with Vallejo medium Flesh and dry brushed with Vallejo Flat Flesh. The sores, tongue, and open wound areas were base coated with Vallejo Rosa and highlighted with Vallejo Salmon Rose. I used GW leviathan Purple inside the mouth to vary it a bit and add depth to the gullet. The gums got a glaze of Vallejo Salmon Rose highlights to tease them out a bit.
The wounds were then treated with a Dried Blood Wash from Secret Weapon then layer highlighted with Vallejo Rosa and Salmon Rose.
The Skin was more complex. It was washed with a different color by skin texture, Warty Patches had Secret Weapon Sewer Water and normal to shredded skin with Secret Weapon Flesh. Once these were dry upper areas of normal skin were highlighted with Forge World ash powder, crevices with Forge World Medium Earth Powder and green shadows with Forge World Light Green Powder. These areas were then damp set and the extended shadow areas had GW Ogryn Flesh Wash applied to for blending.
The Horns and nails were a work up of the Reaper Master Series Khaki triad with a final highlight of P3 Menoth Highlight.
The sword was also done at this point getting the standard "Blighted Weapon" treatment that the rest of the Contagion has. Basically Vallejo Brown stippled with the Reaper master Series fire triad. Some Vallejo Flames of war German Camo brown and German Light Camo Brown with a wash of GW Gryphon Sepia saw off the leather bits.
I went with a chariot base for the time being in part because it'll work out for fantasy battle (although really a 100mm square is more appropriate) and mostly because it'll pack easier for the big move back to the states. I'll likely magnetize the thing and have a fantasy and 40 style base to swap out as needed.
I sprayed the whole thing with Army Painter Anti Shine Varnish at this point (the green stuff based figure above) and the spot varnished the eyes, sores, mouth, and red areas with Vallejo Gloss Varnish.
The figure was a lot of fun to paint and should make a suitably disgusting centerpiece for the Contagion or for a Daemon Host.