CROWN PRINCE'S CONCUBINE - Chapter 666 - 666 The Ancestor

Freshly turned eighteen, John Newman, a helpless nerd, suddenly gets video game abilities granted to him. A mysterious higher power, a secret Abyss of magic beneath the surface of the normal world, mages, martial artists, eroticism, tragedy and a harem of hot girls awaits.

To pass as an imperial concubine, one must be professional.

Actually, the profession of an imperial concubine is pretty good. The emperor will accompany you in eating and drinking, and even pay you for it. What’s not good about that?

- Description from Novelupdates

Just like how everyone adored heroes in their childhood, a certain young man adored those powers hidden in shadows. After hiding his strength and living the mediocre life of a mob character by day while undergoing frenzied training by night, he finally reincarnates into a different world and gains ultimate power. The young man who is only playing at being a power in the shadows, his misunderstanding subordinates, and a giant organization in the shadows that gets trampled…. This is the story of a young boy who had adored powers in shadows possibly eventually reigning over the world of shadows in another world.

An Apocalypse descends—as a lethal super-virus wipes out most of the human population. It took less than a day for the world to change forever—bringing mankind to its knees.It’s a time of misery and death for most, however, there are some who are lucky. Zane Graves, who came across a “Blood Crystal” is given an ability: [Dead Man Walking]—which grants him a special power, and so setting him off on his path to the top!