It's the Relic Envoy from GW's Cities of Sigmar, but where he is meant to be holding a sheathed sword I swapped in an AdMech rifle.
The setting is grimdark WWI with demons and plenty of crusades influence so adding guns and gas masks to AoS minis seems to work well.
A bit slapchop.
I primed it Army Painter black, grey and grey/blue dry brush to make the edges stand out, heavier dry brush plus white dry brush on places to be red or gold.
Reds: Flesh Tearer contrast then another dry brush of Evil Suns Scarlet
Gold: Garaghaks Sewer, Army Painter Greedy Gold
Bone: Reaper Ion Soot (grey), Sepia Wash
Rounded out with: Sir Coates Silver, Guilliman Flesh, Magos Purple, Prismatic Bolt Speed Paint, Army Painter Strong Tone
They were mainly a color test, but I'm pretty tickled with the results.