Coros's Flash Freeze Preservation

You create a flash of extreme cold, instantly condensing a thick layer of ice to encase surfaces and creatures within a 20 foot cube. Frozen surfaces are considered difficult terrain. This flash of cold extinguishes nonmagical flames and can freeze water up to a depth of two feet.

Any small or tiny sized inanimate organic matter (e.g., slabs of meat, a sack of vegetables, etc.) will become petrified in ice and remain perfectly preserved until it is thawed. Once the spell ends, its effects cease to be magical. Any objects or surfaces frozen by this spell will behave like normal ice. In temperatures of 75 degrees Fahrenheit, a 1 foot cube of ice will usually melt within 6-10 hours.

A creature within the spell's area of effect must make a Dexterity saving throw. On a failure, a creature takes 3d6 cold damage and is restrained in ice for 1 minute. On a success, a creature takes half as much damage and is not restrained. At the beginning of each of its turns and every time it is hit with an attack for the duration of the spell, a frozen creature can attempt a Strength saving throw to free themselves from the ice. On a failure, a creature takes 1d6 cold damage and continues to be restrained.

Creatures which are immune to being restrained but are made of freezable material (e.g.; a swarm of rats or a water elemental) are not immune to being restrained by this spell. If a creature's hit points are reduced to 0 by this spell, its body becomes petrified into solid ice.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the area of the cube increases by 5 ft. and the damage increases by 1d6 per slot level above 3rd. As a 4th level spell (25 ft. cube, 4d6 initial cold damage, 2d6 recurring cold damage), as a 5th level spell (30 ft. cube, 5d6 initial cold damage, 3d6 recurring cold damage), etc.