Definition: Crystoleum is a fictional concept in the video game "Overwatch" and its universe. It's an entity that exists as a 3D model of ice, resembling the crystalline structure of crystals. In Overwatch, it is used to represent the concept of "crystallization," which refers to the process by which certain substances undergo changes or transformations into other forms. This concept can also be applied to any substance that is in its state of being crystallized, such as ice