Blade of Vicious Shadows

A blade of piercing shadows answers your call in the shape of a gilded rapier. 

For ten minutes the blade will protect you. If held in hand, you can use your action to make a melee spell attack with the weapon, which does 3d10 necrotic damage.

If allowed to float freely, the weapon attacks on your bonus action, has a range 30ft, and does 2d8 necrotic damage.

After ten minutes has passed, or the blade is dismissed, the weapon dissipates into shadowy whisps.