Staff of Withering
Staff (arcane or druidic focus), rare (requires attunement by a cleric, druid or warlock)

This staff has 3 charges and regains 1d3 expended charges daily at dawn.

The staff can be wielded as a magic quarterstaff. On a hit, it deals damage as a normal quarterstaff, and you can expend 1 charge to deal an extra 2d10 necrotic damage to the target. In addition, the target must succeed on a DC 15 Constitution saving throw or have disadvantage for 1 hour on any ability check or saving throw that uses Strength or Constitution.

Versatile. This weapon can be used with one or two hands. A damage value in parentheses appears with the property—the damage when the weapon is used with two hands to make a melee attack.

Damage: 1d6 (1d8)
Damage Type: Bludgeoning
Properties: Versatile
Weight: 4