MTL - What to Do When I Become a Koi and Fall into the Male God’s Bathtub - Chapter 14 His reader

The Sword Emperor’s challenges result in three of the Ten Venerables to be criticially injured. Three of the Seven Absolutes also die.“It wasn’t enough for you to come knocking at my door all alone; now you dare challenge me to a battle to the death? I did not think you to be so dull as to miscalculate others’ strength.””Neither the Ten Venerables nor the Yellow Lotus Temple’s Seven Absolutes of the orthodox sects had the ability to give me an answer. You are the only one left to ask.”Some may call the Sword Emperor old-fashioned, but he only seeks to be stronger as a martial artist.His endeavor eventually leads him to challenge the Heavenly Demon, the generation’s strongest man in murim. The challenge turns out to be the grand finale of his life.However, the Sword Emperor later wakes up as a member of the Cardenas family, the continent’s best swordsman family!

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 mysterious teenager who had lost his past, awakened in Tianlong Continent. Mistaken as the Ye family’s Son, he used this identity to observe this chaotic world and to search for his past self, but only to find an inevitable and terrible fate, therefore he indignantly laughed at his destiny, and revealed his prowess to rule the lands under the heavens.

Since then, the air and the clouds moved with his hands, and even thunderstorms were subject to his palms! He, as the fairytale’s main character, had shocked the people of Tianlong Continent with his legendary prowess and intelligence, but the extent of his powers were still unknown.

- Description from novelupdates

This is a world where science and magic coexist.

Some people here seek powerful magic, and some seek eternal truth.

A science tyrant who came from another world, started as a little librarian, with magic in his left hand and truth in his right, kicking the door of the new century with one kick.

Some people call him the forerunner of magic, some say he is the founder of science.

Some people describe him that way.

In the new century, Blair is a symbol of evil.

- Description from novelbuddy