My Dungeon Life: Rise of the Slave Harem - Chapter 5

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.

What would you do if you could shuttle the plane?

Gao Linhao got an artifact that can shuttle the plane, so he reached the pinnacle of life, and became an existence beyond everything, just suffering from the unrecognizable planes that Lin Hao had given to evil!

Ji Linhao said, “I want to change as long as it makes me unhappy!”

- Description from Uukanshu

To rise from defeat; to revive amidst the dissipation.

“Brother Katakuri, I’m sorry, I don’t want to bear the name of Charlotte for a long time!”

“Ace, your flame is too weak!”

“Akainu, magma is dessert to fire dragons! Why don’t you understand this?”

The man who ate the dragon fruit, the traitor of the Charlotte family, sprinted towards the title of One Piece!

- Description from novelbuddy