COTE : There is Something Wrong With Hikigaya - Chapter 276: Becoming a Proper Corporate Slave

Fear breaks the boundaries between dreams and reality, and it is impossible to tell which is reality and which is illusory. When the nightmare really comes, no one can be alone.

This is both a danger and an opportunity.

- Description from novelbuddy

The antique market that is filled with treasures and trash.

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.

After what seems to be a plane accident,

Su Bai Master Su was seized of his power and unexpectedly reincarnated onto a cowardly distant nephew.

Who said that you will lead a dull life after rebirth?

The ‘Jade-Faced Yama’ who once ate both the black and white path

vows to take back the power that once belonged to him step by step.

Do you really think Master Su is a rice dumpling for everyone to push around when he does not display his wrath?

- Description from Novelupdates