Chapter 3: Hero summoning
Over 50 years ago, after the mysterious angel brought the world back together and placed a shield around reality itself, Hakiaas—strange monsters that once destroyed the world—began to show up again.
They came in small numbers, slipping through the cracks of the shield with the aim of terrorizing the world from the inside out.
How these monsters were able to appear was still unknown, but one thing was certain—before the monsters slipped through, a countdown would begin, indicating the start of the monster surge and ending when the gate closed.
On average, it took over 10 minutes for the gate to open and close.
Meaning that for ten minutes, the world was being flooded by monsters.
Humans had no way of fighting these creatures; all they could do was stay on the defensive.
That was until the world discovered the beautiful priestesses blessed by the angel herself.
With the power of the angel, they were able to summon four powerful heroes—each hero summoned by a particular priestess.
And though these heroes were able to defeat the monsters, they could not fully kill them, as Hakiaas could not be slain. To make matters worse, most heroes barely lived past 20 years.
Thus, a hero summoning was done every 20 years with the help of the priestesses.
Though only the chosen priestesses could perform this ritual, Eri was simply one of the chosen.