Dread Staff

Wondrous item, artifact (requires attunement by an evil spellcaster)

This shriveled, ebony wood staff is bound at both ends with black adamantine. Runes of liquid shadow cover its surface, oozing and moving constantly. It is a +5 quarterstaff that inflicts an extra 1d6 necrotic damage to a living target. It also is an unholy weapon; when you hit a celestial or a good dragon with it, that creature takes an extra 2d6 necrotic damage. (At the Gm’s discretion, certain particularly good creatures such as paladins might take this damage even if they are not celestials or dragons.)

As your action, you may cast any one of these spells from it, using your spell save DC: conjure celestial (except a fiend instead of a celestial), create undead (8th-level slot), disintegrate, divine word, or finger of death.

When you are touching the staff, it emits an aura of faint shadows in a 30-foot radius around you (this doesn’t affect the illumination level). Your allies and minions are limned with faint shadows; they have advantage on saving throws, and other creatures have disadvantage on attack rolls against them. If a celestial or good dragon strikes a shadow-limned creature, the attacker must succeed on a Constitution saving throw or be blinded for one minute.

Sentience. The staff is a sentient neutral evil weapon with an Intelligence of 14, a Wisdom of 18, and a Charisma of 18. It can see, hear, and perceive with blindsense and darkvision out to a range of 120 feet. It can speak and communicate telepathically.

Personality. Like its former master, the staff wants to corrupt goodness into evil, enslave and conquer whatever enemies it can, and destroy or imprison those it cannot.