MTL - Conan: Open the Door, I’m a Policeman - v3 Chapter 47 Unspoken rules?

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

One moment I was a grown man—an engineer with a decent job and way too many spreadsheets. The next? I woke up in a kid’s bed, staring at glow-in-the-dark stars on the ceiling… in Malibu.Turns out, I’m Jake Harper now. Yeah, that Jake Harper.“Wait… I had a bitchy mom and a simp dad?”Yeah, the behaviors don’t make sense — just roll with itYeah, the years don’t match — just roll with itpatreon.com/MHJunior(I am not the owner of any show, credits to their respective creators)

Cultivating his power by slaying demons and taming countless beasts, the emperor solidified his throne as the world's ruler. But not once in his life had he expected that his disciples would use research on demonology to sap the world tree's power and push the world to destruction.Trying to fix his mistake, he opted to use all of his cultivated power to cure the world tree and block anyone from sapping its power ever again. But in exchange, he was to lose all of his power.But...the worst had happened, his wife... had betrayed him.

Arin, an ordinary office worker, used to dream of a ruined world where humanity was forced into deadly games for the amusement of [Constellations].Then those dreams became reality.As monsters descend and scenarios begin, Arin finds himself one step ahead, holding knowledge of the future others don’t have.But in a world where standing out means being watched, his knowledge quickly draws dangerous attention… from beings far beyond human.Including three powerful Vampire Queens.Follow Arin as he uses his knowledge to survive brutal scenarios, grow stronger, and carve his own path through the apocalypse… alongside the Vampire Queens who have taken an interest in him.