Advil's War

[Group Drama], [Dark Fantasy], [Cthulhu-like] Idleville, an ordinary world. Every two hundred years, the demons living at the two poles of Edvil will launch an expedition in the name of the devil. The nations of Edvil can only rely on summoning brave men from other worlds to resist the disaster. In AD 3007, a brave summoning ceremony secretly performed by the secular government failed, and only an unknown body was found at the scene, as well as a whispering Trigonoctahedron puzzle box. Hell discovered Advil, and the malicious Firstborn also glanced at this place from the corner of their vision...