The world must contain it's internal balance,the dead shouldn't be revived.It's the law of  alchemy and no one must ever cross the line.

"To obtain something,

you must present something in the equal value...

and that is the principle of equivalent trade"

Paranormals have to protect their identities from the outer world surface which is called earth.Normals would do whatever it takes to distinguish anything that’s different to what’s normal because to them,Paranormals aren’t the same.They were despised and weren’t accepted for hundreds of years until to this very day.