Arifureta Shokugyou de Sekai Saikyou (WN) - Volume 2 Chapter 2

What would you do if you were to wake up one day to the message?

[You have 5 days until the next full moon]

[Your bloodlust is increasing]

Gary Dem is a person with a secret. While coming back to school appearing as a whole new person, he does everything he can to keep this from the people he cares about. For his path is one that led him to become part of the underworld.

The world has changed, and gangs rule the streets sponsoring big corporations. Bribing politicians behind the scenes and controlling the decisions people make without them knowing it. Using a new breed of humans called the Altered, a mixture of man and beast.

It was only meant to be a side job, he was never meant to dig in too deep, but on a mission for his gang, something went wrong, something changed him.

[You have 5 days until the next full moon]

[Your bloodlust is increasing]

The lone wolf… is about to go on a hunt!

A 21st-century tech manager, accidentally thrust into the body of Emperor Commodus—yes, the infamous villain played by Joaquin Phoenix—has one goal: not to die like him.Armed with his wits and a hyper-intelligent AI on a solar-powered laptop, he must navigate the treacherous politics of ancient Rome. Everyone, including his own sister, expects the arrogant, decadent tyrant. Instead, they find a calculating reformer. But as he tries to avert the fall of the empire, he discovers that being a “good” emperor might be even more dangerous than being the monster everyone is waiting for.

Reincarnated as the eldest son of Ming Taizu Zhu Yuanzhang, the biological father of Emperor Jianwen, and the elder brother of Ming Chengzu Zhu Di.

See how Yiwen Prince Zhu Biao, who was fleeting like a meteor in history, survived the turbulent Hongwu years and built a new Ming Dynasty!

(No system, no plug-ins, no IQ crushing, no cross-age technology tree)

- Description from novelbuddy