After Beth decided to sacrifice everyone in Kaositer, she had already made up her mind to flee the Western Region with her trusted followers.
Since she wasn't planning to stay, she naturally didn't care what effect the sacrifice would have on the entire western part of the continent.
But after she lured more and more people over, a tiny accident, a small oversight, brought the whole sacrifice to a halt.
That little accident was none other than Wizard Shaya, whom Beth had captured long ago and whose Spirit Body was being controlled by the Inverted Tree.
After hearing Shaya's account, Thor looked the Spirit Body up and down. "You... how did you manage that?"
Shaya said, "It's my secret weapon. I can't tell you."
Thor didn't press him. "All right. You're not my goal anyway. But there's one thing you have to tell me. What's causing your current state?"
Shaya grew agitated. The idea of explaining his vulnerability to someone else seemed to upset him.
But when he thought of his situation, he quickly gave Thor an answer.
"After the Inverted Tree sucked in my soul, I managed to retain some independence, but I still had to obey many of Beth's commands. I was careful not to expose myself, and only occasionally did things of my own to preserve my sense of self."
"Later, I realized that the entire Inverted Tree was absorbing the souls of the city's residents. I knew I had to find a way out. As long as I remained trapped here, sooner or later I'd end up like the other absorbed souls, becoming nourishment for Beth and the Inverted Tree."
"So I planned to wait a few months, until Beth went to the very center of the Inverted Tree again. Then I deliberately removed a crucial