Breath sealed.
This feature is actually quite important.
When Kamiyagawa was active in Hai Zhi Guo, the aura of Ame-no-Ohabari stored in the Mirage Pouch leaked out, catching the attention of Kanihime and Isohime. Even earlier, the Spider Mother Goddess of Source Earth could directly perceive that Kamiyagawa carried a Deity's remains.
Although, given the situation at the time, it wasn't necessarily a bad thing.
However, as Kamiyagawa gathered more high-grade artifact materials, if the aura of these materials couldn't be sealed, he might resemble a walking treasure chest?
It's never wrong to avoid flaunting your wealth.
The benefits of this upgrade far outweigh the downsides.
