I’ve Led the Villain Astray, How Do I Fix It? - Chapter 264

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

In a world where everyone changes jobs, I actually awakened to a unique dual career.

And a life-defying career?

High-quality items to cherish? I synthesize directly.

Cherish high-quality skills? I synthesize directly.

Senior pet cherish? I continue to synthesize, wait, how did this beast girl become so big after synthesis?

Let’s start with the synthesis of three skeleton summoning books…

Synthesis – [Undead Army]

Three more dark staffs to synthesize…

Synthesis – [Death Scepter]

The game competition of billions of races in the universe, our solar system, can we earthlings stand on a broader stage!

…

- Description from novelbuddy

[sexual content and lemons warning]Warning: Sexual content, lemons, Comedy, MILFs, Genius Mc and his harem.Support the novel by adding to your library and with power stones!!*****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.