Apocalypse: I Built the Infinite Train - Chapter 50: Soaring Skyward!

Eren Idril died as an old, decrepit, and piss-poor adventurer by the maws of a D-Rank monster. He had a lot of unfulfilled dreams and desires that couldn't see the light of the day after the light in his own eyes died down.

But fortunately for him and unfortunately for the world, that wasn't his end. Eren was somehow dived back in time when he was a mere teen, attending Lionheart Academy for adventurers.

When life gives him a second chance, Eren decides to exploit it to its fullest. Experience his vile deeds as he partakes in them without feeling the slightest bit of hesitation.

Shen Yaowei was an idiot her entire life, and was finally sent to death by the person she trusted the most. After being reborn, Shen Yaowei was no longer silly. She just wanted to cling to the future tyrant and live a life of luxury. Possessing almighty skills and being known as a foolish girl, Shen Yaowei pretended to be an idiot and went on a killing spree, abusing the scumbag until he cried for his mommy and daddy. Anyone who stopped her from clinging onto the tyrant would have to die. Soon, everyone discovered that the frightening Prince Li, who had always been a loner, had changed. There was always a small shadow following behind him. “Ninth Uncle… I don’t have the strength to walk. I want you to carry me…”

the little shadow spread her arms towards His Highness, looking pitiful. “Yaoyao, I’m strong so I’ll carry you!” her elder brother, leader of the martial arts alliance, arrived at the battlefield instantly. “No, I’m stronger! I’ll do it!” her second brother, a miracle doctor, came forward. Then her third brother, fourth brother, fifth brother… All the bigshots had arrived, asking for hugs and to let them carry her. “All of you, get lost! That’s my darling daughter, so I’ll carry her!” Her father, a great general protecting the country, rushed as fast as possible to Shao Yaowei’s front, only to find that the aloof, noble and peerless prince had already knelt with his back facing Shao Yaowei. “Come on, Yaoyao. I’ll carry you.”

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.

Once upon a time, an Alchemist Grandmaster from the World of Immortals accidentally took possession of a playboy, who hailed from a rich and powerful family, and became a student in the middle of his midterms.

By the means of a miraculous immortal technique, he blended in and mingled amongst the femme fatales’ group to dominate the city! The nature of this novel’s origin is shamelessness to the core; having no sense of shame is just a basic foundation, but if the most shameless isn’t set yet, then become it!

- Description from Novelupdates