Toaru Majutsu no Index: New Testament - Volume 6, ???

Fanatic virtual gamers:
Tired of the stereotyped linear drama emotions? Want to try a real open world game?
Are you tired of playing an RPG that can only play a role? Want to lead the subordinates in virtual reality and experience the thrill of governing the army?
Welcome to the massive open killing game “War in Heaven”.
……
Seeing the game’s winning and losing judgment mechanism, a professional player who is interested in PVP for 20 years and is also very interested in AI, has a bright smile:
“It’s time to show the real killing method… How about building an AI army by the way?”

- Description from Uukanshu translation

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

He lived like a king, died like a grandpa... and woke up as a bratty villain inside a fantasy novel.Nice.Born into the mighty Arkanveil family, he’s expected to grow up spoiled, arrogant, and doomed. But sorry, fate — he’s got better plans.Armed with a broken Proficiency Panel, two god-tier Traits, and the mind of a seasoned conqueror, he’s here to rewrite the script.Demigods plotting. Councils scheming. Demon Emperors laughing.They’re all just EXP waiting to happen.Pretending to be a clueless baby genius, he secretly trains, conquers, and stacks power like a final boss.Because this time, the EX-Rank Villain isn’t playing to survive.He’s playing to win.The world’s greatest families have no idea what’s coming. But hey... they’ll find out soon enough.“EX-Rank problems require EX-Rank solutions.”

The Age of Celestials has arrived.

In the world where Vincent was sent into, the existence of Celestial Beings greatly stimulated the advancement of humanity. With their help, the humans started breaking out of their shackles as they exceeded the limitations of their mortal bodies.

They have passed down mana cultivation techniques and various combat arts increasing their strength as they fought against the true enemies of the world…

However, as Vincent was sent by his grandfather to complete a very unusual mission, he learned that these majestic Celestial Beings weren’t gods or existences out of his reach… They were actually tools or weapons that humans have been using for their own greed. More than that, he discovered the true origin of the Celestials!

Hence, with the help of his System, he mounted a rebellion…