Voltedge

Damage: 1d8 (V:1d10) Slashing + 1d4 Lightning
Modifiers: Melee Attacks +1, Melee Damage +1
Once per day, when you hit with this weapon,
you may mark your target, dealing an additional
2d4 lightning damage.
For one minute, any time the marked target is
within your reach and makes an attack against a
target other than you, you may use your reaction
to make a melee weapon attack against it.
Requires Attunement.