Aralius' Surge Serpent

You conjure an enormous serpent built entirely of lightning energy. Select 8, adjacent five-foot squares starting next to you. Each creature in one of these squares must make a Dexterity saving throw. A creature takes 8d6 lightning damage on a failed save, or half as much damage on a successful one.

At Higher Levels. When you cast this spell using a spell slot of 4th or higher, the range increases by 2 five-foot squares for each slot level above 3rd.