Blizzard

You release the power within to become the center of a raging otherworldly blizzard. In a 20-foot radius from you, the area becomes heavily obscured for any creature other than you, and difficult terrain for any creature other than you. Any spell of 7 level or lower that deals fire damage has its fire damage halved, any spell that deals fire damage of 3 level or lower has its fire damage reduced to 0. Any exposed flame is extinguished. Medium or smaller flying creatures or objects can’t pass through the wall. Loose, lightweight materials brought into the wall fly upward. Arrows, bolts, and other ordinary projectiles launched at targets within the sphere are deflected and automatically miss. (Boulders hurled by giants or siege engines, and similar projectiles, are unaffected.) Creatures in gaseous form can’t pass through it. If a creature starts and ends its turn within the blizzard then it takes 2d10 points of cold damage.