Arianwyn's Arctic Cowl

You conjure a blizzard around you to bolster yourself and hinder your foes. It extends out from you 20 feet in every direction, and heavily obscures its area. Other creatures in the area are vulnerable to cold damage, and must spend three feet of movement for each foot they move. In addition, you gain 20 temporary hit points, +2 AC, and may make one weapon attack as a bonus action, which deals an extra 3d6 cold damage on a hit.