How about a magic taser for DnD 5e?
Lightning Cuff Links
Wondrous item, rare (requires attunement)
These silver cuff links are each made in the shape of a lightning bolt. Once per day, when you are struck by a melee attack, you can cause the lightning within to discharge. The attacking creature must make a DC 15 Dexterity saving throw. On a failure, the attacking creature takes 5d8 lightning damage, is pushed 15 feet away, and knocked prone. On a save, the creature takes half damage, is not moved, nor knocked prone. If you take at least 20 points of lightning damage from a single attack, the cuff links recharge. Otherwise, each morning at dawn, you hear distant thunder, and the cuff links recharge.
Throat Punch Games 