Magika no Kenshi to Shoukan Maou - Volume 13 Chapter 1 — Nightfall’s Cthulhu (Part 1-3)

Others treated disease to save person, he treated disease to steal heart.

The Frost Goddess was deeply captivated by him. The gentle and kind beautiful teacher was completely enchanted by him. Even the cold and beautiful female assassin melted quietly because of him.

Competing in medical skills? He was the one who treated the Godly Doctor. Competing with backgrounds? Leaders rushed to him. What? You actually wanted to compete with him in a match for match? Looking at the gentle girl beside him, Tang Yu had a headache as he said, “Beautiful girl, how did you fall in love with me?”

- Description from Novelupdates

He was the CEO of the Mu’s Group. He had a respectable status and a domineering attitude. His biggest weakness was that he doted on his daughter. For his precious daughter, he came to her and signed a contract for her to be his daughter’s nanny. She thought it would be fine to stick to the contract, but he interfered more and more with her, driving away every man around her without leaving a trace, locking her in his arms, saying to her affectionately and tyrannically, “We should give a companion to our daughter.”

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.

I was a genius in the Earthen Plane.