One Piece - I Am A Different Luffy! - Chapter 465 - 463 - The Wano War 03.

On her wedding night, framed for infidelity and to be burnt alive?Chu Qianli laughed heartlessly, “I've already written the divorce letter for you, farewell.”Feng Yexuan seized her firmly, his cold and sinister voice cutting through the air, “Thinking of leaving? The only way out is over my dead body!”…The Divine Doctor unexpectedly transmigrated into the unlearned Princess of Prince Xuan, and Chu Qianli only wanted to live an easy life without any ambitions.But she inadvertently caught the attention of the obsessive and insane Prince Xuan and accidentally got spoiled to the heavens!One day.The officials approached with gloomy faces, “Prince, the Princess is causing chaos in the Golden Hall again, please reassert your authority!”Feng Yexuan knelt before his wife with a thud, presenting a “taming husband whip” with both hands, “Lili, I've ripped their mouths for you, can you be a little gentler?”

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.

One day, a villainess came to the orphanage.“I absolutely can’t stand children!”“How can someone my age have a child? It doesn’t make sense!”“What’s so great about these little creatures that tire you out all day long…”Setting aside her dislike for children…Somehow, after she arrived, the children started gaining weight.“It’s all because of the contract, you know?”That’s what she says.While personally feeding them sweets she made herself.

Bags of salt, spices and sugar stacked from inside the shop all the way out into the streets. Merchants loaded with goods going flooded the streets with their carriages.