No Hero - Volume 2, Legend of a Hero Chapter 2: Late at Night, the Busy Hero

Pain, Pain, Go Away is a novel by Sugaru Miaki, also known as Fafoo, author of Starting Over and Three Days of Happiness. Unlike Miaki’s previous two books, Pain, Pain, Go Away is not a rewrite of any story posted to 2ch, but an entirely original one.

The plot involves a young man who becomes a killer (by accident) – but his victim has the power of “postponement,” temporarily delaying her death.

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.

At the beginning, he became the most famous prodigal in America. Facing the danger of going bankrupt, how could Chen William turn the corner and become a big shot in the fame and fortune circle?

- Description from novelbuddy

She is an international ace agent,An amazing doctor, God of Assassination, However due to a box she accidentally rebirthed and became an ordinary junior high school student. Weak and incompetent, That scum woman wants to put her head into the toilet. The gambling father, borrowed a lot of money and now they are being chased by loan sharks for debt? There is also a group annoying people in her life. The reborned Yunxiao sneers: I want to know how to write the dead words! She returned from the wind, high-profile attack, if people dared to bully me, they are courting death!