Eldritch Weapon

The weapon you use in the casting of the spell becomes sheathed in eldritch power - causing it to be a conduit for your patron's magic. For the duration, you can use your spellcasting ability instead of Strength or Dexterity for the attack and damage rolls of melee attacks using that weapon, and the weapon's damage die becomes a d8. The weapon also becomes magical, if it isn't already. The spell ends if you cast it again or if you let go of the weapon.