Ethereal Blade

You create a blade of ethereal energy in your hand, similar in dimensions to a longsword, which lasts for the duration of the spell. As an action, you can make a melee spell attack with the blade against one creature within your reach. On a hit, the blade does 2d6 radiant damage plus 1d6 cold damage.
If you let go of the blade, it disappears, but while the spell is in effect, you can create it again with a bonus action.

Enhancement: When you cast ethereal blade using a spell slot of 4th level or higher, the damage increases by 1d6 radiant damage for every two levels above 2nd.