Djerg Nurn (5e Equipment)

Weapon (longsword), legendary (requires attunement)

This blade, which translates to “Dwarf friend” belonged to an elf who traveled with a dwarven expedition to the Underdark. Although initially mistrustful of him, the dwarves changed their mind when the elf sacrificed his life to save the expedition from a colony of mind flayers, earning him a Dwarven burial of honor, and recognition as a hero among the dwarves.

You gain a +3 bonus to attack and damage rolls made with this magic longsword. It deals an extra 2d6 lightning damage, or, if the target is a fiend or undead, 3d6 lightning damage. While you hold the drawn sword, you have advantage on saving throws against spells and other magical effects. As an action, you can unleash a 30-foot cone of destructive energy from the weapon. Each creature in that area must make a DC 18 Dexterity saving throw, taking 10d6 lightning damage on a failed save, or half as much damage on a successful one. Once this action is used, it can’t be used again until the next dawn.