The Demon King's Army Arrives in Reality

The magic circle drawn by humans using witchcraft and alchemy actually summoned monsters... The monster that had just been summoned slaughtered the humans around it and then disappeared without a trace. Perhaps because the magic circle and the corpse were not erased, later generations wrote stories about him and founded the Knights, but the danger was coming quietly. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.