Heroic spirits are the beings whose great deeds have been left as legends after death, and have become the objects of faith. Usually, the Heroic Spirits are called by the world as a force to protect humanity. And what humans are calling is the Servant.

The so-called guardians are the heroic spirits that the "world" uses as a restraining force. Guardians will be summoned by the world to annihilate the main cause after the main cause of destruction of the world is generated. The main cause of the destruction of the world is also the human race, and the guardian will kill all the people related to the main cause of the destruction of the world after the present world, and protect all other human beings. Since the Heroic Spirits of the human faith are classified as Guardians, it is easy for those who have made a contract with the world to become Heroic Spirits. Restraint is something different from the Constellation of the Valhalla. It is created by the collective unconscious of human beings, and in order to perpetuate the human world, they are the defense institutions that treat human beings as slaves. Those who conform to the will of the restraining force will be called to be called as guardians forever after death. Heroic Spirits and Guardians are both souls that have ascended to the "throne", and the difference between the two is that Heroic Spirits are called by people's hope, and Guardians are called out by people's despair. A person who becomes a hero by his own merits or sins alone is not bound by restraint. But the powerless person, the one who lives and laments his powerlessness, and the one who pursues the power above himself, is bound by the power of restraint. Inhibition is a contract of consideration, giving a "miracle" to a person who laments powerlessness, and temporarily shaping that person into a hero. As long as that person is "a person who has something to do with the survival of mankind", it will give him an infinite amount of magic and opportunities to use as a tool to sustain human history. In return, the soul that temporarily became a heroic spirit after death will be taken away. That is, the "completion of the soul" that will not be redeemed after death.