Auriel's Crystal Core

This crystal is emanating a cold mist, icy to the touch yet hard like a diamond. By focusing you can grow this crystal into any shape or cause it to disintegrate into back into the small crystal.

Crystal Forge. While attuned, as an bonus action you can form any simple or martial melee weapon or return it back into the state of just a crystal. This weapon deals cold damage instead of whatever damage time it would deal ordinarily. 

Curse. The cold permeates through to your very core.