Kureto is a creature called a curse. Curses come from people's imagination and are the embodiment of false creatures fabricated by ancient humans for spiritual sustenance. They condensed and grew in human thoughts over the years, and finally broke out of the shackles of the virtual world and came to take shape in the material world of human life. They were endowed with the same organic and thinking abilities as all creatures on the earth. All in all, the curse here is a special life form that should not exist in the first place.
However, Ji, as a human, accepted him.