The sword has 6 charges and regains 1d4 + 2 expended charges daily at dawn. While holding the blade, you can expend 1 or more of its charges to cast one of the following spells from it, using your spell save DC and spellcasting ability modifier: gust of wind (2 charges)

Air Rend. This weapon can manipulate the air around it to generate blades of wind, delivering devastating slashing attacks from range. When you take the Attack action, you can choose to make a ranged weapon attack with this weapon on a target up to 15 feet away. 

The wind billowed around the warrior. His blade was drawn but at his side — a harmless target. The drow licked her lips and drew the bow silently. Poison dripped from the arrow's tip, hissing quietly as it hit the ground.

Suddenly, the air around the man exploded, and a gash in the air came barreling towards the archer. Her eyes widened before narrowly dodging aside. The branch she had been perched upon now a mass of splinters.

She turned her attention back towards the man, the blade still seemingly motionless at his side. She loosed one arrow after another only to see them destroyed before ever reaching him.

When he moved, the air seemed to stand still and bend to his will. His purpose was clear: she, the assassin, was going to die instead.

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

Notes: Damage, Combat, Versatile, Sap