And that accident happened on a day more than fifteen hundred years ago.
For a long time, the impurities infiltrating the dark side were "filtered" by the nighttime power of Tsukuyomi, so their impact was weak.
But on that fateful day, things were quite different.
A large amount of exceedingly potent impurities swept out from the barrier after the midnight snack, even threatening to completely engulf the dark side.
Kaguya herself did not possess the great might of Tsukuyomi. Inheriting two Divine Remains Bones was quite arduous. Moreover, the crisis came unexpectedly, without the slightest sign.
Therefore, in the end, she did not handle the accident perfectly.
Although the massive and strong impurities from the Shinshusado were eventually purified and eliminated, the impurities dispersing from the "Nest" returned to a weak and impotent state. Yet, the "Waning Moon" Divine Bone responsible for absorbing impurities on Kaguya was eroded by impurities.
