Aquatic Razor

You summon a wide arc of high-pressure water that you hurl forward. Each creature in a 10-foot wide and 40-foot long line in front of you must succeed on a Dexterity saving throw or take 8d6 force damage on a failure, or half as much on a success

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3.