I've Got A Mana Processor In A Magic World - Chapter 7: Recruits

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.

One day, a silver-haired goddess appeared before him.“Heaven-Defying Star. The one who goes against fate. The sole savior of a world doomed to end—”What the hell is this woman even talking about?“You must be the Regressor.”“… What?”No, I’m not.

The world spat on him because he betrayed humanity and took the side of darkness.His executioner was his best friend and his lover stood on one side, her eyes hollow and devoid of any sympathy.Every single one desired him to vanish.However, the moment his pitiful life came to an end he found himself getting summoned by a Goddess.Kneeling on the ground and requesting for his help,[For the last time, please wear the mantle of our champion again. This world needs you, Clarsen.]So she said.The world would be pushed under the darkness of death again, and this time there would be several chosen warriors there to save the world.Yet, despite all that, the eldest Goddess was begging for his support.“Fine, I will do it myself.”********Additional tags: Strong to stronger, ruthless MC, kingdom building, limitless mana, possessive characters, regressor, transmigrator, obsessive love.*********A/N:- Give the story a read until it goes through a time skip. I request you to pass the judgment after that.

“Great Mr. Chen Yu, having been successfully elected as the leader of the human race last night, do you have anything you’d like to say to the whole world?” Chen Yu got out of bed, bewildered and still undressed, “I don’t know, I just woke up...”