Azurwraith, Vengeance of the Breaking Storm

Forged in Ancient times from the old wars, made from Black steel and imbued with the power of lightning and death, this sword was once one of justice but as been long since cursed soaked in the blood of thousands now and taited by dark magic,  Every swing of this sword invites death, and when close to it, you can feel the cold grasp of death, the weight of all those that have been slain by this blade.

You gain a +2 bonus to attack and damage rolls made with this magic weapon. When you hit with an attack using this magic sword, the target takes an extra 1d6 lightning damage. In addition, while you hold the sword, you have resistance to lightning damage.

Dark lightning: The sword has 4 charges. While holding it, you can use an Action to expend 1 charge to make a ranged attack in a 60 feet by 5 feet wide line in a direction you choose. Each creature in the line must make a Dexterity saving throw. On a hit, the target takes 4d6 lightning damage and 4d8 necrotic damage on a failed save, or half as much damage on a successful one. If this damage reduces a creature to 0 hit points, it is reduced to ash. On a natural 20,  you may as a reaction use the Dark lightning ability, The sword regains 1 charges at dawn.

Lightning Rod. When you take lightning damage, roll 1d20. On a 10 or higher, the sword regains 1 charge.

Proficiency with a Longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage: Lightning, Resistance: Lightning, By those itself deems worthy, Damage, Combat, Sentient, Versatile, Sap