I like this. Very flavorful and not immediately overpowered (though I need to check on inhuman vigor). If anything, all of my critiques are to strengthen some options.
I particularly like Deny Weakness and Evil Eye.
I feel like stonehide needs a bit more. Perhaps consider giving an item bonus to unarmored defense at 5th, 11th, and 18th levels. 99% of players are still going to take armor runes, which wouldn't stack with it, so it would mostly be a flavor adjustment anyways.
Heed the Spirits is a bit weird. It says you have to roll the next attack, skill, or saving throw roll, and that you have to take the new roll. How is that any different than simply rolling once in the first place? If it was a reaction or free action in response to a roll, that would make a little more sense.
Winter's Fury seems a bit weak for a level 13 feat. Compare the action cost to damage ratio for something like Ray of Frost, considering that you need to make multiple further actions/reactions and attack rolls to approach the cantrip's damage.