Chains of the Firmament

Choose a point within range. A cylinder with a 100-foot radius and unlimited height is centered on that point.

When this spell is cast, all creatures in the area with a Fly Speed have that Fly Speed reduced to 0 and it cannot increase for the duration of the spell. If a creature is airborne when the spell is cast, it descends harmlessly at a rate of 100 feet per round until it reaches the ground.

Creatures native to the Elemental Plane of Air, as well as creatures with no Speed other than a Fly Speed, are immune to the effects of this spell.