Sadistic Pauldrons

Wondrous item, common (requires attunement by a barbarian)

These rough steel pauldrons are twisted and scarred into horrifying spikes. Whenever you are struck by a creature with a melee weapon attack, you can use a reaction to lean into the blow, taking 1d4 additional damage of the same type you just took, but deal 1d4 piercing damage to the creature that dealt the damage. While you are under the effects of your Rage class ability, the damage you both take and receive from this effect increase to 1d6 piercing damage.

Adaptive Holy Symbol

Wondrous item, uncommon (requires attunement by a cleric)

You can cast a domain spell from a Divine Domain that you do not have, that you are of an appropriate level to cast. This still expends a spell slot of the appropriate level. You can use this ability once before needing to complete a long rest to use this ability again.