Entropic Reaper

The wood of a quarterstaff you are holding is imbued with necrotic power as you utter an incantation and a curved black blade of necrotic energy forms at the end of the staff making it resemble a scythe. For the duration, you can use your spellcasting ability instead of Strength for the attack and damage rolls of melee attacks using that weapon, and the weapon's damage die becomes 2d4. The weapon also becomes magical, if it isn't already. The spell ends if you lose your grasp.