Epic of Caterpillar - Chapter 10: Overpowering Sun!

“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

5 years after the world changed, the final boss appeared.

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.

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.