the human realm is as normal as it gets but an organization that has existed from the beginning of time isolates a terrible truth, the bitter truth of all that has existed is nothing more than just an illusion,
demons are known to have a history with wars, as far as the eye could see the demon realm had been a target of massacre, disorder, destruction, and chaos,

as history repeated itself justice and evil against each other gave birth to endless wars since demons existed finally both rulers of the two kinds of demons established peace together and just when there was hope for a new beginning tragedy struck! and so...

In the present era the entire criminal world aka "The Underworld" is the property of Devel aka "Then King Of Criminals", since the mysterious disappearance of their ruler the unholy demons serve a supernatural being with god-like abilities known as "The Dark Lord", who declares a universal war, thus the universe is moving towards another war for some may call it "THE FINAL ORDER"
the only thing that ensures anyone their victory is "The Holy Blade Of Gizel", and so everyone strove for it

leaving the poor naive humankind unaware of the coming war
however, as they all thought that they had it all... the blade was revealed to be in the possession of...

and that's just the start!