Crown of Deep Winter

This icy crown is made using ice from the Everglacier. While wearing the crown, you have resistance to cold damage. In addition, you can use an action to cast the fire shield spell from it, making only a chill shield when you do. Once the crown has cast this spell, it can’t cast it again until the next dawn.

Frozen Burst. While wearing this crown, you can use your reaction when a creature within 5 feet of you that you can see hits you with an attack to cause the area around you to explode in a burst of razor-sharp icicles. When you do, all creatures within 5 feet of you must make a DC 16 Dexterity saving throw. On a failure, a creature takes 2d8 cold damage, or half as much on a success. This property of the crown can’t be used again until you finish a short or long rest.