Ary'Faern'Kerym

The blade appears as if made of darkness, and its shape is a tangible black void, outlined in a crimson streak which is the source of the blade's light. It crackles like lightning when drawn, and creates a sharp buzzing sound when swung, like that of an angry bee. Oddly, when the blade strikes a foe, there is no sound from the hit, despite the strength behind it. An elven rune near the pommel signifies a thing of magic on the pommel is A selu'kiira was an intelligent gemstone that stored knowledge of its past wielders
(does 2d6 Lighting +2 Int +1 History)

In battle the blade could be used as a weapon while still allowing the wielder to cast. The blade channeled the bearer's magic acting as their material focus and used the wielder's swing and its own buzzing to complete the casting.

In 500 DR, the elven noble and bladesinger Josidiah Starym embarked on a famous quest to retrieve the Warblade from the Twisted Tower with a band of his adventuring friends but when he returned in 674 DR he had found the Artblade instead.[6] Josidiah bore the Artblade until his demise in 714 DR during the Weeping War and the fall of Myth Drannor, when the blade was consumed in a great magical attack by the Starym noble.

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

Notes: Damage: Lightning, Bonus: Choose Constitution or Intelligence, Bonus: History, Damage: Slashing, 25000 Gold, Elf rite, Damage, Combat, Versatile, Sap