This is a protection ring that holds a sentient curse, who goes by the name Yerrick. 

Yerrick will feign ominous omens and builds meaningless tension. Only you can hear and see him for the most part.

He has a +6 save against remove curse.

Once per long rest you can choose 1 out of the 3: 

a) As a BONUS ACTION, have Yerrick help you analyze 1 opponents' actions and strategies in order to get advantage on your first attack against that target on your next turn

b) Hide as a BONUS ACTION

c) He will give you advantage on an intimidation check by either coming out of the ring or possessing you. If he possesses you, he will be taking the wheel for the next 6 turns. Roll a D20: with a 10 or below, you are possessed; with an 11 or above, Yerrick just appears out of the ring for that turn and you decide whether everyone can see him or just you and the target.