A certain eccentric Diabolus performed an experiment.
What will happen if you put mask that gives human supernatural power and murderous impulse onto non-human—
The experiment ended in failure, since souls with low intelligence was unable to withstand erosion from the mask. However, the last specimen showed a different reaction. Although the subject—a cunning Predator that has reaped many lives—could not avoid the collapse of its ego, its grudge-filled grief transformed the mask and formed a "crux".
The eccentric Diabolus embed the ominous "crux" into their own eye, and gained dominion over both the mask's will and the Predator's will.
It is said that the madness of this person who developed their desired world as a "domain" is available in the Black World's dark recipe site "Crookpad" among those in the know.