Romance Game: Embrace of the Inhuman - Chapter 374 - 343: It Is Discourteous Not to Reciprocate

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.

Follow Benjamin Joyce, an elderly man with a passion for blacksmithing who spent his life travelling the world and learning new things. Now, after helping out the developers of the first ever real VRMMO game, he gets the chance to play said game earlier than the majority of other people.

What happens when you transmigrate to Beast World? With the system in hand, the world is for your taking! One day, Su Tang, an intern at the hospital, is struck by a system and transmigrates to Beast World. It's a wondrous world with winged tigers, fire-spitting birds, and enticing man-eating flowers… Everything in this world leaves Su Tang awestruck!After the Chief of Winged Tiger Tribe saves Su Tang, she learns how backward this place was. Su Tang is determined to help change the world! Under the system’s guidance, she helps to extract salt, build homes, dig traps, make weapons and store food for winter… And perhaps even save the world while she's at it!

Reborn in the early 1980s, what Lin Xia wished to do was to be “idle” to the extreme, and so wealthy that it dripped off of her...Having another chance at life, all she wanted was for her brother to live a long life of a hundred years, her younger brother to attend university, and to set up a small business for her sister;Yet, why were two highly eligible men taking turns to express their feelings for her?