A Sweet Marriage Is Worth Billions: Mysterious Young Master Moh's Cute and Sweet Wife - Chapter 85

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 on my way home with my friend when suddenly, I spotted a catgirl cosplayer who made my heart skip a beat.But something felt off—I couldn’t recall seeing her in any anime, manga, or games I had ever come across. Confused, I asked my friend standing next to me.To my shock, his response sent chills down my spine:“Huh? What catgirl? What are you talking about?”Suddenly, a truck came barreling toward the girl. Without thinking, I rushed to save her. In the end, both of us were hit by the truck.Now, I find myself reincarnated in another world—in the body of the very catgirl I had seen.But... who is this girl?How is she related to the dungeons that keep popping up in this new world?

There’s an ancient saying in Great Ruins, ‘Don’t go outside when it’s dark.’

As a successful villainous BOSS, in addition to having ideas and aspirations, one must also keep in mind three points:First, grow sneakily, don't act rashly (once a villain acts rashly, they basically won't survive past three chapters).Second, you're not a good person, so be ruthless (becoming more evil will make you three times stronger, while redemption weakens you by seven times).Third, remember the two points above. The moment you forget them, your end is probably on its way.