As for the base I went for the bone fields bases from Secret Weapon Miniatures for my DC, so I wanted Lemartes to be consistent with his crazy brothers. The problem is he already brings a sort of pedestal that wasn't really fiting with the bones bases, so instead I used an urban rubble base from SWM too, which also has a skull or two around it.
So I just carved a line for the metal indentation below the mini, filled the gaps with some greenstuff and added black lava from vallejo on top of it to give it a sandy texture. I'm sure GW will soon release a resin version, in the meantime the metal minis are best kept with their metal tab, or won't last long attached to their base.
Painting is very straightforward sporting a black armour. I primed it black with an airbrush and Vallejo's black primer, which gives it a nice, thin layer that doesn't cover the details. The metal areas were painted with mythril silver, mainly in the armour joints, and boltgun metal for the larger parts.
For the parchments, skulls, feet bones and purity seals, I began with a brown basecoat and then a layer or two of thinned bleached bone. This is important as we want the brown base color to still be there. Next comes a good wash with Devlan mud will do the dirty job, and a finally some light highlights with bleached bone.
The red areas were painted with a mechrite red, followed by a thin layer of 50/50 mechrite / blood red then more devlan mud. After having used GW paints for 15+ years, Devlan Mud is clearly the best wash ever available. Reach out to your LGS before all the stock is gone.
As for the armour, a good basecoating will do most of the job. Just added some light highlights with 50/50 codex grey/abbadon black, followed by spare touches of SW grey for the more extreme lights.
The base is also fairly straightforward. I used a foundation brown, probably calthan brown, to give it a muddy look, followed with codex grey for the big stones. This is the same scheme I'm following for the rest of the army anyway. Then washed it again with my favourite paint -you know what I'm talking about!.
At this point I added some pigments from SWM. Just used an old brush to add some touches of different browns / greys, then fixed them with a MIG product. If you don't have pigments, some drybrushing will do the job. I've recently gotten onto pigments and they are GREAT for weathering and basing. The final touch is a bit of reallistic water in a small area. Note the greenish look below the water - just added a bit of green pigment to break the monotony of brown and black.