As a bonus action on your turn, you can unfurl wings of shadows. When you do, you can choose any number of creatures within 15 feet of you to make a Dex save. A creature takes 2d6 cold damage equal to your level on a failed save, or half as much damage on a successful one.

Your transformation lasts for 1 minute and it only has 3 charges. 

During it, you have a flying speed of 40 feet. Once on each of your turns, you can deal extra cold damage to one target when deal damage to it with an attack or spell. The extra fire damage is equal to your level.