Savra, the Withering Nightmare

This staff has 3 charges and regains 1d3 expended charges daily at dawn.
It can be wielded as a magic Quarterstaff. On a hit,
you can expend 1 charge to deal an extra
2d10 necrotic damage to the target. The target
must also succeed on a DC 15 CON saving throw
or have disadvantage for 1 hour on STR and
CON ability checks and saving throws.
"Rot, in the name of Zamorank"- Zamorank, the cruel