Arc Weapon (5e Equipment)
From D&D Wiki
Weapon (Any melee weapon), Rare
A weapon with a set of discharge cells to allow the stunning and shocking of targets.
When you deal damage to a creature with this weapon, you can expend one charge to deal an additional 1d6 Lightning damage and force the victim to succeed on a DC 15 Constitution saving throw or be Stunned for 1d4 turns.
This weapon has 6 charges and regains 1d6 at sunrise.