The characteristic of "Time Freezing" magic was a gem watch.
Many types of magic needed to use a certain kind of material as a catalyst, and the "Time Freezing" was not an exception. Aside from a gem that many types of advanced magic needed, it also needed a watch with accurate time. The specific shape and size didn't matter, but it just needed to run accurately.
To cast magic conveniently, casters usually used a special pocket watch with many gems inlaid. It ran very accurately so it fully met the requirements of this magic.
Among the known magic, the material to cast this magic was unique. Therefore, whenever a caster took out a pocket watch during battle, they mostly wanted to cast this magic.