The Shelf Life of My Truth Is Only Thirty Days

Revelation given by gods often requires mortals to pay a heavy price. But Liebert doesn't think so. There is no light from the gods, nor whispers from the devil. Every time the full moon alternates, his mind will be forcibly filled with a bunch of absurd, weird, but accurate "truths from another world" that make the gods tremble - the most terrible thing is that the shelf life of this knowledge is only thirty days. After thirty days, the truth is mercilessly cleared and randomly refreshed again. Until the end of a certain month, when the full moon comes, the knowledge is emptied again. Lord of the Abyss: "Great Sage! I have led the Abyss Legion to the city. Where is your supreme magic formation?!" Libert (looked blankly at the architectural drawings he drew last month): "What is this? Did I draw this miracle?... Don't worry, my brain is starting to itch again. This month's truth seems to be called...[Criminal Investigation and Counterespionage]?" Libert sighed, silently pushed up his glasses, and patted the podium: "Students, put down the staffs in your hands. Today the teacher will teach you how to enforce the law against the Abyss Lord who sneaked in."