MTL - I Am Invincible From the End of the World - Chapter 888 first battle (below)

Travel across different worlds and become a fallen aristocratic lord. With the help of the proficiency panel, you can start your liver experience with the ancestral knight breathing method, follow the wizard’s footsteps step by step, and embark on a bizarre and mysterious journey.

- Description from novelbuddy

Everyone has friends in their lives, right?They can be anyone—good friends, bad friends, or even... friends with benefits.Ahem!Anyway, the point is, everyone has friends. And so did I.I was friends with author of web novel.Yeah, was.A small argument over how the main character should act in novel of [World’s Greatest Hero] led to a fight with my friend, the author.Still frustrated, I stormed out of his house... and that’s when Truck-kun hit me.But that wasn’t the worst part.The worst part? I woke up in a different body—the body of a side character in my friend’s novel.A character who is supposed to die in the prologue.[Your body is dying!][You don’t have much time left.][The creator of this world is mocking you.]F#ck you, Author.F#ck this novel.I will survive, and when I do—I'll beat you to a pulp!

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.

Q: How would you approach your target?

Tiger Tribe:
Jiang Yu (excited): “Cure him, give him medicine!”

Future Mecha:
Duan Jingzhe (at a loss): “… umm … feed him expired nutrients?”

Ancient Court:
Donghao Yang (banter): “Follow nature’s example and flirt shamelessly.”

Next unlucky protagonist: “…”

This is a collection of three short stories in which each protagonist crosses to another world or is reborn.

- Description from Novelupdates