Hidden Marriage 99 Days: Please Restrain Yourself - Chapter 2

Fate, a gatekeeper who had been working for the castle, is beset by a few burdens.

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.

Nan Gong Xi was a top national secret agent who found herself transmigrated as a female prison guard who inherited her mother’s business.

Her father was the warden, her younger brother was a junior officer, and her mother was a retired housewife. Her family had served as minor officials in the capital city for generations.

She had no special abilities, only memories from her past life. But exceptional people will shine through effort, no matter their background.

Watch as Nan Gong Xi, now called Gong Xiao Hua, grows from a junior guard into a female general of the kingdom.

Qin Chu Yuan came from a prestigious family line, blessed with talent and looks. Outwardly gentle, he was scheming on the inside.

The one correct calculation he made in life was marrying his one and only wife, Gong Xiao Hua. She fell right into his trap.

From then on, the married Qin Chu Yuan became a devoted, doting husband catering to his wife’s every need – to the point that onlookers grew tired of their affection.

Kamishiro Homura is a hero who once by himself exterminated the another world invader that destroyed the military all over the world. However his extreme strength made the influential people ostracized and exiled him from the society with false accusation of [Traitor] attached to him. A few years after that, for an unspecified reason Homura entered the magician academy and he looked after the girls that were ridiculed as the [burden platoon]…!? This is the raise of the curtain of a fantasy tale of the unrivaled and invincible young man where not a single ally or enemy can keep up with him, the young man who sooner or later will be extolled as the messiah by the whole human race!