I do like the poncho and since he's a shaman I could see it being something for religious purposes. Maybe it's to keep gore off him while cleaning skulls, maybe it's for ceremony (we do know them to wear capes), but it's this cool detail that you can make stuff up for. I don't think I actually need an answer for the poncho though, I just like that it's here.
Fairly certain Neca gave him a potential Wolf mask. If that's the case it's cool it's brought back here. I'm just saying it's pretty close to be coincidence