My Seven Wives in One Body and Me, her Manager - Chapter 34: Strategies for The Game

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.

The king of assassins was reborn, mastering both alchemy and poison. Sitting inside the space, there was a ghost that loved crying.

Traveling to Tokyo in the second year of the economic bubble, he was adopted in an orphanage at the age of twelve and became a fifth-grade pupil at Heiwa Elementary School.

There is no One Punch Man, no Conan’s nirvana when he arrives at the scene, no system, no golden finger, the only fun in life is to go fishing with Tian Kongkui, the little albino girl next door, and occasionally deliberately score zero in the test Ben Yukiko’s mother was angry.

Wrote “Walk in the White Night” famous in the world?

Sorry, too much homework, no interest, finish writing and go fishing.

How about singing “lemon” and breaking arms with Kimura Takuya, or taking part in “Love Letter” to take away the male lead role of Takashi Kashiwahara?

Please, don’t you sleep well for a while, and go fishing in the afternoon.

“School will be closed tomorrow, Tian Kongkui, remember to put on the most beautiful little white dress. I will also put on a tie and a white shirt. After meeting at three o’clock in the afternoon, I will leave on time.”

“?G? Are you going to participate in the JunonsuperBoy star draft?”

“Idiot, let’s go fishing together.”

……

“People are in Tokyo, don’t fall in love”, “From the countryside of Tokyo to a national idol”, “I’m a primary school student, that’s all”, “Madam, can you sit far away from me?” “It’s better to buy karaoke money Bait, so I sang a cappella on the side of the road”

- Description from novelbuddy

That night, she was dragged to the Bureau of Civil Affairs. Wait, after getting the marriage certificate, the husband ran away? And his identity can’t be found? OMG, did she marry a human or a ghost?

Disheveled, she entered the entertainment industry and almost got sexually assaulted by a director due to the unspoken rule. Young Master Moh suddenly reappeared, and that director was tortured before getting cancelled.

During a shoot, she almost died since her enemy wanted to destroy her. Then, hundreds of mysterious soldiers arrived and smashed everything. The producer was exposed of corruption and his life got destroyed.

She always fights back and takes revenge, not taking the high road.

What? A woman is after her man? No tolerance! She barged into that woman’s home and whooped her ass. She said afterward, “How dare you touch my man?”

Young Master Moh had to cover his forehead; he needed to teach her how to behave like a senior officer’s woman.