MTL - I, The Grandson of Garp, Scared Luffy Into Tears - Chapter 722

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.

Six years ago, the legitimate daughter of the Chu Family was schemed against by her half-sister and was forced to marry the Princely Heir, who was blind and not long for this world.Fortunately, her medical skills were excellent, and she detoxified the Princely Heir.Who would have thought after he came back to life, the emperor would actually want to bestow a concubine upon him—and this jerk didn't even refuse.Furious, she left a divorce letter and then set the Prince Residence on fire, fleeing in haste.Six years later, the same Princely Heir remained a lonely man, with all his old servants worrying their hearts out.One day, upon encountering a Little Baozi on the street who looked strikingly like the Princely Heir, they instantly burst into tears.“The Prince Residence has a successor! Princely Heir, please come back with us to the Prince Residence quickly.”Who knew, Little Baozi disdainfully said, “Not interested.”“Princely Heir, the Prince Residence is immensely wealthy...”“My mother is the wealthiest person!”“Princely Heir, the Prince Residence is extremely safe...”“My mother is the Martial Arts Alliance Hierarch!”“Princely Heir, the Prince Residence has powerful armies...”“My mother is the heir to the Nanduan Kingdom!”Suddenly, a faint voice came from behind: “Then, does your mother need an Imperial Consort? I think myself quite suitable.”

The 27-year-old genius beauty doctor Xia Qing dies in surgery!She is reborn!She is reborn in the ward she’s most familiar with, in the body of a 200-pound pregnant woman—a woman who had died from pain during a Cesarean section due to her requests to not use anesthesia.She can’t help but worry about herself. This body was useless except for being young.How could Xia Qing tolerate this?On the menu are—revenge, losing weight, and snatching the idolized man of a scumbag girl in passing. Although she’s overweight, she strives to live well. Being overweight isn’t the end of days. They still deserve love.“Have you heard? Boss Pei has a child out of wedlock. He’s getting married!”“Who’s he marrying? Who?”“That 200-pound fatty from the Lin family of South City!”“Is Second Master crazy?”Lin Xiaqing turns her head to look. “You think I’m fat?”

99 is one, and nine refinements are returned to Xian.

A young town boy, stepping on Xiuxian Road, is not a family, no gold fingers, with his own determination and wisdom, the nine major cultivation system, the nine realms step by step to the peak, and finally ninety-nine one, the achievement of true immortal.

- Description from Uukanshu translation