When thinking about prehistoric humans, many people imagines stinking, mucky half-wits garbed in raw animals skins, at best clumsily stitched into crude skirts ar dresses.
Reality is somewhere else...
First from the left is Lionman garb for rituals; I imagine Lionman to be minor spirit/deity, and Nir´s role as him is more passive/support (he is "tied" on the place). The mask is cave lion skull, black color is probably grease, soot and some musk mix. Rest is made from bleached leather with lion claws on forearms and lion tail sewn to pants to add to lion vibe; the red mane are Nir´s own hair artfully tousled into shape.
For less important rituals Nir uses whatewer clothes fits to current weather; the main parts are shrike facepaint, three braids hairdo with red deer spine ended with adder head, decorated with rook feathers; the leather bracelet marks him as shaman appreitience, as the headband do (the headband is meant to symbolize wearer´s problems, to remind him to fight it; Nir portraited his pains by thorny blackthorn branch with little skulls impaled in shrike-like mannner). And under it is the ritual drum with "opposites" themed drumsticks.
Next two garments are everyday outdoor ones from horse/reindeer leather and furs, decorated with lether stitching and dying by cinnabar in the sape of Nir´s scarring (good for recognizing one´s clothes too). Second one actually fits into the first, boot included; the pants of the winter suit are double lethers, filled with fur and feathers. The ungainly cape is from mammoth skin on the outside to repel snow and wind and is lined inside with rendeer skins (actually the best against cold, as the overcoat hairs are filled with air). The mask from birch bark protects wearer against the snow blindness and frostbite. The snowshoe is also very necessary back then.
In general, Nir likes to wear baggy, loose clothes to hide his skinny build, also he tries to hide his leg stump all the time with sewn shut pants legs, slings and long shirts.