One Piece: Path to Power - Chapter 82: [] Big News!

Roan transmigrated as an FBI investigator.Several years later, a journalist interviewed the world-renowned detective Roan Greenwood and asked,“What made you persist in solving cases for so many years?”Roan tilted his head and glanced at the sports car beside him, the villa behind him, and the beautiful woman inside the villa. He smiled slightly and said,“Well, the bonus after solving the case.”“What?”

Mu Jingzhe transmigrates into a book filled with sweet, doting love to become the useless supporting character who serves as a foil to the female lead. She also becomes the stepmom of five kids to her recently deceased husband.

“Aiyo, this time someone’s going to die. This is going to be a big deal.”

She had transmigrated, and her architectural style had transcended into that of a village girl. How could she be so ungrounded?!

When she opened her eyes, she saw a group of people beating her up.

Mama, who can tell her what’s going on?

That patched up but handsome shy man actually liked her?

- Description from Novelupdates

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.