He has been a "killer" since he was a child. In order to survive, he personally wiped out the life of his compatriot sister and buried him together with his heart at the bottom of the deep lake.
His appearance was like a taboo, easily breaking his indifferent defense. Forcing him to choose to perish together with him.
However, the pain of infertility completely obliterated the meaning of his existence, and he resolutely chose to leave.