The Almighty Rich Daughter is Explosively Cool - Chapter 676 - True Selves

Kim Hyun Woo lived the life of the wealthy thanks to his parents. But one day, he received a phone call informing him of a traffic accident which involved his parents. His father had died and his mother was hospitalized in critical condition. The normal life he once knew, collapsed…

They sold their house, cancelled various insurance plans, and moved to a one room apartment. And after a few years, Hyun Woo spends four to six hours tending to his mother and worked to pay for her medical bills.

One day, one of his Instructors recommended him for position in a company called Global Exos, who made an announcement of making history with the newest technological invention.

Reborn and returning, he possesses medical skills, can practice immortality, has a slave who is the king of killers, and a maid who is the school beauty pursued by everyone. Even casually taking out a piece of trash can shock the world. His return has set this world ablaze.

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.