Thunder Blast

Lightning descends on a creature that you can see within range and explode upon impact. The target must succeed on a Dexterity saving throw or take 1d6 lightning damage. The target gains no benefit from cover for this saving throw. the lightning arcs towards enemies within 5 feet of the original target and can only spread out to enemies equal to the number of your wisdom modifier dealing half the damage towards the new targets rounded down of the original value upon the first target.

The spell's damage increases by 1d6 when you reach 5th level (2d8), 11th level (3d8), and 17th level (4d8).