Dark Senechal

The bladed weapon you are holding is imbued with powers of dark stewardship. For the duration, you can use your spellcasting ability instead of Strength or Dexterity for the attack and damage rolls made using that weapon. The weapon becomes magical, if it isn't already and also deals Necrotic damage instead of Slashing or Piercing unless you choose otherwise when casting this spell. If you cast it again the spell ends. If your turn ends and you are not holding the weapon the spell ends.