Urannon's Thunderbolt

A swirling, thin, black cloud apparates in the sky, creating a 15-foot-radius, 100-foot-high cylinder centered on a point within range directly below the cloud. Lightning strikes below the cloud, hitting the entire area. Each creature in the cylinder must make a Dexterity saving throw. A creature takes 8d4 lightning damage on a failed save, or half as much damage on a successful one. The spell automatically fails if you do not have a large enough area (i.e. 100-foot-high cylinder with a 15-foot-radius).

Targets in the thunderbolt's area of effect that are wearing metal armor or are made of metal have disadvantage on their saving throw. If a target is wearing metal armor fails it’s saving throw, it is then paralyzed until the start of its next turn. Objects in the area are scorched black from the strike.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the lightning damage increases by 2d4 for each slot level above 4th.