A black, sharp, and wicked looking horned crown. Upon it one can see various glyphs and symbols of a large assortment of gods, main ones being Moradin, Tyr, and Mystra.

Mind Domination: As an action, you can force the target creature you can see to make a Charisma saving throw(a willing creature can fail automatically) against your spell save DC. If it fails the saving throw: you can communicate with it telepathically over any distance(it doesn't have to understand any language) and you always know if it's telling a lie.
This connection lasts until broken by you(no action required) or the two of you are on different planes of existence for longer than 1 day. The target can repeat the saving throw every 7 days, breaking the connection on a success.
If the creature is not willing you must expend a charge, if it's also of higher CR or level than you, you must expend additional charges equal to the difference. This item has a number of charges equal to your proficiency bonus, you only regain them after a connection to a creature that you expended charges on is broken.

Mind Shatter: As a bonus action, you can choose a creature you are connected to, it must be on the same plane existence as you. It takes 4d6 psychic damage or is stunned until the end of its next turn. You can use this feature a number of times equal to your proficiency bonus, regaining all uses upon finishing a long rest.

This item belongs to the Witch-Kings Regalia set, they use the same attunement slot, When attuned to all items in the set, you gain the following:
Expand Consciousness:  As an action, you can perceive the surroundings of a creature you are connected to as if you were there. If it is in combat, you can participate(on initiative count of 20) as if you were in its location, you can only use cantrips, spells, or spell attacks. It is only aware of this if you choose so.

Limitless Mind: The number of charges of Mind Domination and Mind Shatter is doubled. You regain one charge of Mind Domination every 30 days.
Additionally, your mind cannot be read or manipulated by any means, you cannot be charmed or frightened in any way.

Notes: character that has Spellcasting or Pact Magic feature