The Reincarnated Assassin is a Genius Swordsman - Chapter 541

A civil engineer reincarnated into a magical land and tragically became a Wood, Earth, and Water Sorcerer.While still questioning where his [Earth Bear Bloodline] originated, the Chosen One next door summoned a 'player'...Watching others lead extraordinary lives, Hill just wanted to hide away.

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.

[Beef buns: Can effectively replenish physical strength, enhance fitness, and are safe to eat.]Hungry Tain Lin looked at the cow dung in front of him and couldn't help but fall into contemplation.Is this cow dung or a beef bun?To eat, or not to eat? This is a question.

Mimizuku, a small girl with chains on her wrists and ankles and the numbers “332” branded onto her forehead, wanders into the Forest of Night seeking to be eaten by a monster. However, when the ruler of the monsters, the mysterious and beautiful “King of Night,” refuses to eat her, she tries to formulate a way to convince him otherwise.