Dancing Shadow Blade

You create a flying weapon made of shadows within range that lasts for the duration or until you cast this spell again.

When you first cast the spell, you can make a melee spell attack against a creature within 5 feet of the weapon. On a hit, the target takes psychic damage equal to 1d6 + your spellcasting ability modifier.

As a bonus action on your turn, you can move the weapon up to 20 feet and repeat the attack against a creature within 5 feet of it.

The weapon can take whatever form you choose. 

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for every two slot levels above 2nd.