MTL - Unfathomable Doomsday - Chapter 141 Continuation of the royal family

In the winter of Taikang Year 3, a girl pays a visit to her future in-laws, the Ning Family of Beiliu, Yangcheng.

After her engagement was denied, the girl decided to hang herself in front of the Ning Family to show them her sincerity.

When the girl who had died opened her eyes once more, many people’s fates were changed forever.

- Description from Novelupdates

After getting forcefully reincarnated into a world of an otome game he has no clue about, the protagonist is then killed and brought back to life by the prideful villainess with one desire.

To rule the world.

As the ruthless girl’s Eternal Servant, how will he dodge the fate that the game system has in store for him?

Feng Yun transmigrates into a fantasy world filled with magical powers and immortals.Just as he was wondering about his future, the system activated...[Ding, activation confirmed. The novice gift package will be issued automatically.][Ding, congratulations to the host for obtaining a random special physique: Sacred Dao Body of Chaos.][Ding, congratulations to the host for obtaining the Supreme Foundation Building Treasure.][Ding, congratulations to the host for obtaining a hundred million top-grade spirit stones.][Ding, congratulations to the host for obtaining an immortal grade soul-strengthening elixir.]Hahah... money, power Immortality, beauties, I am getting all...

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.