Painted those on my iPad while traveling Norway.
The "explorer" was a quick model and Maya render at home, of which I put several renderings on my iCloud.
The main inspiration came from Norse Mythology, and the "Dark Fields" of Niðavellir.

It was a super fun experience to paint those outdoors!
And if you are interested in the photos I used for those you can check out my Norway reference pack! :)
https://www.artstation.com/ingraban/store/dOdb/norway-reference-pack