Arc Lightning

Make a ranged spell attack against a creature within 30 feet of you. Tendrils of electricity launch out from your fingertips towards the target. On hit, that creature takes 1d6 lightning damage, and you may make another ranged spell attack against a different creature within 15 feet of the first. On hit, that creature takes 1d4 lightning damage.

At level 7, the first bolt deals 1d8 damage, the second bolt deals 1d6 damage, and it bounces one more time dealing 1d4 damage. At level 13 it deals 1d10 damage, second bolt deals 1d8, third deals 1d6, and it bounces a fourth time dealing 1d4 damage.