Metabot's Manual of Magical Maneuvers

Fangs of the Storm Serpent

4-level Transmutation

Electricity pulses from your hands and envelopes your blades in bright sparking energy. You can use your spellcasting ability instead of Strength or Dexterity for the attack and damage rolls of attacks with these weapons, which each deal an additional 2d6 damage lightning damage the first time you hit with the weapon each turn.
Additionally, a magical connection is forged between each weapon and the hand that holds it. After using an action or bonus action to make an attack with one of these weapons, you can teleport the blade back into your hand or teleport up to 30 feet to where the blade struck a creature.