Encase

You touch one creature, which has to make a Dexterity saving throw against the spell save DC or be encased in ice. While the creature is encased in ice, it is restrained and takes cold damage equal to 2d6 + your spellcasting ability modifier every round until the encasing ends. 

The spell lasts for the duration, or until someone uses an action to free the encased creature by ending the restrained condition. 

At higher levels. If you cast this spell using a spell slot higher than 2nd, the duration of the spell increases by 1 round for every spell level above the 2nd.