1. is the evolution of mankind (but it is a failed evolution).

2. orpheus's success rate of increasing his companions by killing people is very low. The purpose of establishing Meteor School is to cultivate elite orpheus. Collect orphans first, then give them a good education, then let the powerful orpheus kill them when they grow up, and finally implant orpheus marks on them to transform them into orpheus. As a result, the experiment failed. Only one of so many Meteor Sect members succeeded in becoming orpheus (the cost was too high), but made many enemies, so he could use orpheus's belt as a human being.

3. After the experiment of Meteor School failed, Meteor School was abandoned, and the school was buried underground in order to bury the evidence.