Eldritch Blade

The metal of any weapon you are holding is imbued with dark energy of unknown origin. 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, the weapon's damage die becomes a d8, and the damage is replaced with Force. 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.

The spell's damage increases at higher levels, with 2d8 at 11th level.