Maybe the end goal isn't to kill guwon but instead change his mind on how to lead the community
The second is that teach is the reason the cycle keeps continuing. They keep killing guwon in each new life which leads to everyone being killed and then teach blames it on himself, jumps off the cliff amd repeats the cycle. But in the past, once it resets, he forgets most things but a part of him doesn't. Hence why he tried to kill himself multiple times.
I have 2 theories
Maybe the end goal isn't to kill guwon but instead change his mind on how to lead the community
The second is that teach is the reason the cycle keeps continuing. They keep killing guwon in each new life which leads to everyone being killed and then teach blames it on himself, jumps off the cliff amd repeats the cycle. But in the past, once it resets, he forgets most things but a part of him doesn't. Hence why he tried to kill himself multiple times.