Path of the golem

For some barbarians, rage comes from the minerals and metals from nature that seeps within their very soul. Those barbarian's strength lies in their resilience akin to a mountain.

Rock Polish

Starting at 3rd level when you take this path, while raging and not wearing heavy armour you gain +1 to your armour class until the start of your next turn every time you make an attack against a creature.

Iron Wall

Beginning at 6th level, While raging, when a creature you can see withing 60ft of you is attacked by another creature you can use a reaction to increase his armour class by your rage damage bonus for this attack. If this increase causes the attack to miss the attacker is pushed 10ft away and knocked prone. You can use this feature a number of times equal to your proficiency bonus, you regain all expended uses on a long rest.

Crystal body

Beginning at 10th level, You become immune to poison damage and the poisoned condition, you also become resistant to psychic and necrotic damage and can choose whether to count as your creature type or as a construct when targeted by spells and other magical effects

Heavy metal

Starting at 14th level, You reduce all non-magical damage by an ammount equal to your constitution modifier and magical damage by half as much (rounded down).

Additionally if you take damage you are resistant to you can use your reaction to take 0 dmg instead, you can do so once per long rest.