The wearer is healed, up to their HP maximum, 50% of all melee damage done to any creature that is not a construct or undead. The wearer is drained of HP by 50% of all melee damage they inflict on undead. Damage on a construct has no effect either way. The wearer is immune to all magical healing and can only spend one hit dice per day of natural healing (Second Wind or similar counts as that one dice). If the wearer removes the ring all disadvantages remain for 24 hours and you lose attunement. After the 24 hours have passed the ring can be attuned again.

When this ring is worn for the first time the above is known immediately so that the wearer can decide if they wish to attune to the ring.