MTL - First Day In Game, I Got Ten Billion From Infinite Number Of Check-ins - Chapter 523 I tell you

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.

Luck wasn't on his side as when he was just few steps away from becoming the world champion in karate he was killed by his by his opponents scheme who was afraid to fight against him and wanted the cup. But he was once again given a chance to reborn as Kenichi Shirahama and become the strongest martial artist.Watch and see how he conquers the world by becoming the strongest disciple and also how he conquers the women's he likes in his HaremI have reuploaded the chapters again as to the problem of Power stones that occurred in the previous one.

He rose from hardship, but was felled by betrayal. From then on, one man, one gun; treads the path between Evernight and Daybreak to became a legend. No matter what was destined to be his fate, he intends to become the ruler who dictates.

Have you ever heard the story of the monster?

Have you ever thought that monsters have always existed, and they are lurking around you?

Have you ever thought that the reason why you are still safe is because the profession of “Monster Slayer” has existed for thousands of years?

Wang Qianchen turned into a monster when he woke up, and was ruthlessly hunted down by the monster slayers, and since then he has also entered a strange world!

- Description from novelbuddy