ThunderFall

You create a psychic Channel for lightning to flow through your target.Make a ranged power attack against the target. On a hit, they take [roll]2d6[/roll] lightning damage.

At the start of their next turn , a bolt of lightning strikes the target from above.

All creatures within 15 feet of it must make a Dexterity saving throw and takes [roll]10d6[/roll], or half as much on a succesful save.

At Higher Levels

 When you cast this spell using a spell slot of 5th level or higher, the damage increases by [roll]1d6[/roll] for each slot level above 4th.