Marriage contract: Genius baby's belly daddy - Chapter 2591

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.

A decision can destroy the sun, moon and stars. A finger can kill the Heavenly Overlord. While chatting, the Heaven and ten worlds can be annihilated.

“I don’t care what Thanos’ ideals are, and I don’t care what the consequences of having too many creatures in this universe will do, as long as he doesn’t ruin my business with that damn Infinity Glove!” – Kahn Ponte

Once he traveled to the world of American comics, Kahn had the golden finger to trade all worlds.

At this point, the name of Boss Kahn not only resounded in the Americas of the Marvel Universe, but his influence spread to all the worlds!

PS: There are many follow-up worlds such as Marvel, Naruto, Harry Potter, One Punch Man, Black Robe Pickets, Dragon Ball, Pirates, etc. You can decide…

- Description from novelbuddy

From the outside, Nana’s life seemed simple. She had everything she had ever wanted: a cute but rascally pair of twin brothers, a best friend, and her own restaurant. Nana couldn’t ask for anything more; she was happy and content in her life.