These mysterious weapons were unintentionally brought into existence when the Null Gate was shattered at the end of the second Great War. The blades look like jagged pieces of broken glass, they absorb all light around them while reflecting none, giving them a pitch black appearance. You gain a +2 bonus to attack and damage roles made with the magic weapon. When you hit a magical effect, such as the wall created by the spell Prismatic Wall, you can force the caster of the spell to make a DC 15 Wisdom saving throw, on a failure the spell is dispersed. If you hit a creature with this weapon you may force it to make a DC 15 Wisdom saving throw, on a failure the target can no longer use magic, but can still be targeted by spell effects, otherwise the effect is identical to them being in a Antimagic Field. The target can make another DC 15 Wisdom saving show at the end of its next turn, on a success the effect ends, on a failure the effect persists for 1 hour. This item is immune to the effects of Antimagic Field or similar magic. Enemies gain no benefit from magic armor against attacks from this weapon. 

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

Notes: Damage: Melee Weapon Attacks, Versatile