You strike the ground, choosing a point you can see within range to begin accumulating gravity. A 40-foot-radius, 100-foot-high cylinder centred on that point becomes difficult terrain until the start of your next turn. When the spell ends, the gravity reaches a critical magnitude, smashing all creatures in the cylinder downwards; each creature in the area must make a Strength saving throw. If the spell lasts its full duration and ends at the start of your next turn, then, on a failed saving throw, a creature takes 8d10 force damage and is knocked prone. If the spell ends before the start of your next turn, a creature takes 4d10 force damage on a failure instead. On a successful save, a creature takes half as much damage and isn’t knocked prone.