The Royal Military Academy's Impostor Owns a Dungeon [BL] - Chapter 24: Upgrade Requirements

At dawn.The light of dawn lingered, hesitant to arrive, while the remnants of the setting sun had long faded into darkness. Within the city shrouded in thin mist, the hidden churches in the shadows, veins clinging to the cracks in walls, the gnawing sounds echoing from the sewers, and the murmuring shadows...A lantern bearer strolled forward.

He lived from BC to the Middle Ages, from the Renaissance to the Industrial Revolution, and from Cyberpunk to the Interstellar Age. He has been a king and a prophet, a knight and a nobleman, a versatile artist, a genius inventor…
This is a four-thousand-year human epic——
“To us four thousand years from now:
“Is the world at peace? Is famine extinct? Can people touch the stars? How long is the human lifespan? How far is the boundary of the earth? Human…do you remember us?”
——Excavated from Earth Age Tenth Century BC, Solomon Prayer Book.

- Description from novelbuddy

When MC was reliving a picture of a goddess, he died. Only meet the goddess, but instead of torturing him to eternity, she gives him wishes. And make him reincarnated in the Overlord world.As the name suggested, this is multiverse Fan fiction, that means MC will travel through different world like Marvel, DC, High School DXD, My vampire Diaries (may be) , Demon Slayer, etc.first world: Overlord (Chapter: 1—60)second World: Highschool DXD (Chapter: 60—215)Third World: Demon Slayer(Chapter: 216—)Fourth World: New World (Overlord)There will be a harem, no NTR or stuff.Some of you might dislike the Yggdrisil arc as it is a bit of AU and MC talk a lot. But it is only in this arc on world travel that I will tone down his unnecessary internal monologue.I am not a professional writer, and I have no deep experience in writing, so please ignore my grammar mistakes and such. I also took some inspiration from other fan fiction.It would be a great help if you could donate your power stone to me.

A fighting genius.