Vortex of Absolute Zero

Using the weapon known as Longshot, you fire a frost imbued concentrated energy arrow into the stratosphere above the targeted area. The arrow explodes in the stratosphere creating a massive vortex that pulls the absolute cold of space down to the ground of the target area.

Creatures within the area take 10d12 cold damage. Creatures must make a DC 18 constitution saving throw. On successful save creatures take half damage. On failed save creatures take full damage and the Brittle effect is applied.