Learn from your Enemy

Starting when you choose this path at 3rd level, you gain the resistances of your foes when you rage.  While raging you gain resistance to cold, fire, poison, bludgeoning, piercing, and slashing from nonmagical attacks that aren’t silvered.

Frightful Aura

Beginning at 6th level, your rage frightens those are are not used to it.  Any creature you choose that starts it turn or enters within 30 feet of you while you are raging must make a Wisdom saving throw.  On a failure, On a failed save, the creature is frightened until the start of its next turn. If a creature’s saving throw is successful, the creature is immune to your fear aura for the next 24 hours..

Magic Resistance

Beginning at 10th level, your rage flows into your weapons and your very soul.  You gain advantage on all saving throws against magical effects and spells while raging.  Your weapon counts as a +1 version of itself while you are raging.  If your weapon has a better enchantment that +1, use that instead.

Diabolical Apotheosis

Starting at 14th level, when you rage, you take on the visage of a devil.  You gain immunity to all nonmagical weapons, immunity to poison and fire damage and the poisoned condition, giant bat wings that grant you a fly speed of 60 feet per round, and truesight out to 60 feet while raging.