MTL - I am the Father of the Villain - Chapter 5 fifth

Reincarnated into his college days. Zhou Yuwen knew the importance of a persona. In this life, Zhou Yuwen’s labels were aloof, mature, and exceptionally talented! “I’m quite traditional, I believe that if you’re in a relationship, you need to be responsible, so one must be extremely cautious about dating.” “Zhou Yuwen, let’s get remarried!” “Damn it! Are you poisoned or something? I haven’t even been married before!” “Stop talking nonsense! We were married in our last life!” “That was in the past life!” “Remarry!” “Go away! I have a girlfriend!” He fled, she chased! He couldn’t escape, even if he had wings!

Lin Xiao was an orphan who strived to get stronger while living with his sickly younger brother in an unnamed small village.

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.

Xu Jun finally defeated the BOSS–the Dark Demon King, in this stand-alone, virtual reality game. When he wanted to go out to browse Weibo and express his mood, he suddenly encountered a game BUG and immediately passes over to the game world.

He became the man who finally took down the Great Demon King in this world. Gratifying! The attention of millions of people!

……However, he did not know the development of this world was not the same as the game, the Demon King did not die, rather his soul entered into Xu Jun’s body; this Demon King knows of all the stupid things Xu Jun does everyday…….

- Description from Novelupdates