The lowest of them are known as The Faceless.
This is the start of that exploration. A simple miniature from the Storm of Sigmar start set - this set chosen because it's basically dirt cheap - and then some conversion work.
I removed the details of the helm and the obvious chaos god symbols. I then added the chain and created a wound for it to come from.
Normal zenithal priming and some filler and rock on the base.
Here's the painting with the corrosion and rust and various veins and details on the skin.
The last touch was snow on the base for that proper barbarian of the far north look.
And here he is with the Darkoath. I think they go well together.