WOAH! Sasami’s mother is such a MI-
She came back from the world of the dead just to give Sasami a lecture and make her go back to the way of the Tsukuyomi priestess. And not even the Yagami sisters were a match for her:
With Tsurugi cast into the world of the dead, Sasami had no choice but to listen to her mother and go back to being a Tsukuyomi priestess.
I was thinking Sasami caused this Alteration, wishing to see her late mother again… but seems that’s not the case. Someone else also had a hand in it.