Chainburst

When you hit a creature with Aeisparc, you may unleash the lightning within. The target must make a Dexterity saving throw against your spell save DC. On a failed save, the target takes 6d8 lightning damage; on a success, they take half.

After the initial strike, lightning arcs to two other targets of your choice within 30 feet of the original target. These secondary targets must also make the same Dexterity save, taking the same damage on a failure, or half on a success.