Board Thread:Roleplay/@comment-27349558-20161126005629/@comment-24947676-20161127222919

Kana's Soul Gem turned into an egg-like shape when she detransformed.

"Soul Gems tend to do that. When your Soul Gem is in that shape, it can be used as a witch detector. If it glows brighter, then a witch is nearby. You can also turn it into a ring at will, so that you can carry it around easier without it getting stolen by some random normie." Kyubey explained.