Ethereal Slash

A wave of sharp crackling energy streaks toward a creature within range. Make a ranged spell attack against the target. On a hit, the target takes 2d10 force damage.

When used at higher spell levels your mastery of the spell begins to actually cut the target thus adding an additional 2d10 slashing damage: at 6th level 2d10 force + 2d10 slashing, at 8th level 2d10 force + 4d10 slashing.