Staff of the Undying Gazestaff, very rare (requires attunement by a spellcaster)

This staff has a cluster of eyeballs attached to it which have been preserved using Flesh to Stone. While attuned to it all undead within 120 feet of you are outlined in a purple glow for your eyes only. You can see them even through walls or while blinded as long as they are within range. Even if an undead is in the Ethereal Plane you can affect it from the Material Plane if it is outlined in this way. Additionally, you know the types of all undead in range even if you have not seen them before.

Unrelenting Gaze

As an action you can activate this staff, causing the eyes to open. When you do so choose an outlined undead, or another creature you can see within 120 feet of you. The target creature must make a DC 18 Wisdom saving throw. On a failed saving throw it takes 4d8 psychic damage and is Frightened of you until the end of its next turn. If the creature is an undead it is Stunned until the end of its next turn instead of Frightened. On a successful saving throw the creature is not affected.

very rare