Mato-seihei-no-slave Stories

the gates that appeared on earth, were created for a purpose the 'gods of thunder' challenging the humans and anti demon corps was also for a greater purpose there exists a third world, one with many wonders one so technologically advanced it had created the mato for one reason, to cure the boredom of it's populace, now the anti demon corps must face, the coming legions wait, the foremost legion is on their side..................... what the hell