Cosmic Rime

A flicker of ancient starlight from the frozen star Verglasz waxes over the ground on a 10' square centered on a point within range, turning it into difficult terrain by flash-freezing it with a thin, nearly invisible layer of black ice and hoarfrost.

When the ice appears, each creature standing in its area must succeed on a Dexterity saving throw or fall prone and suffer 1 cold damage. A creature that enters the area or ends its turn there must also succeed on a Dexterity saving throw or fall prone and suffer 1 cold damage.

Heat or flame equivalent to 5 or more points of fire damage in the area ends the spell immediately.