Naruto: The Life Changer - Chapter 55 -:

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.

Once the ultimate Soldier King and a supreme assassin, empowered by a magical Magic Bracelet, had mastered Cultivation, Medical Skill, X-ray vision, and foreseeing the future… became an omnipotent master of pretense. Come, come, come, watch the omnipotent master of pretense teach you a few tricks of pretense.A demonic man who walked out of a major foreign prison, yet married a cold Queen-like CEO wife, leading a life where “you glare at me with displeasure, and I look at you with disdain.”

In every story, there exists the hero and the villain, the protagonist and the antagonist.And like every story, the hero always wins, and always gets the girl.But what happens now that I died and became a villain in the last book I read? Not even a proper villain, but one that the protagonist kills in the early chapters.I don't want to die again, and I don't want that simp of a protagonist to walk all over me. Maybe I should just become a better villain.I've always admired the smart badass villains that took on the protagonist. Maybe I can be one of them, maybe I can win—the first villain to win against the hero.I'll rewrite this story into one where I become the greatest villain. Call me sick or evil, but it's my time to shine.

The past life Ji Anran: “Geng Yan, let’s get back together.”

Geng Yan, who was dumped: “I refuse. You have powers anyway, and you can live well without me.”

After rebirth, the weak chicken Ji Anran: “Geng Yan, let’s get back together.”

The dumped Geng Yan: “I refuse.”

Ji Anran, lying dead: “I have no power, you don’t care about me, just let me get cold1.”

Geng Yan: “… …” The unsuccessful Geng Yan can only take away the weak chicken, one cannot put sand on the wall2 Ji Anran.

Later… what about the ordinary person without the strength to truss a chicken?! Who’s the guy in the day?

- Description from Novelupdates