Warlock Apprentice - Chapter 1021 - Permanent Spell

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.

My name is Kaelith Yurei , and I am a first-year student at the Shin'ō Academy in the Soul Society. I have a friend who is destined to be quite famous in the Soul Society; his name is Sōsuke Aizen.Unlike this ambitious and idealistic friend, my goals are quite simple: through hard work and diligence, I aim to graduate and become a seated officer in the Gotei 13, from which point I will… I bounded with who!?Whenever Aizen enhances his strength, my power automatically synchronizes to match his level.Therefore, what I need to do from now on is very clear.“Sōsuke, you need to work hard. As long as you put in enough effort, I can live the life I desire!”

“Even death can't stop me from reaching the top.”Alex clawed his way to the top through sheer hard work and ruthlessness, only to be betrayed by someone within his own group.Although he managed to kill the traitor, he lost his life in the process.But just when Alex thought it was the end, fate had other plans for him.Reincarnated into the world of a novel his girlfriend used to read, he was given a second chance at life.His goal remains the same, but this time, he awakened a mysterious system and surrounded by a harem of alluring beauties.Follow Alex journey through this vast new world as he uncovers the truth behind his reincarnation and the otherworldly goddess who made it all possible.

The protagonist is reborn in the late Roman Republic and becomes a gladiator under Spartacus. How will he escape the tragic fate of being crucified, and how will he survive in the Mediterranean ruled by Rome? Stay tuned!

“Rome must fall! As long as it exists, we cannot escape our fate of death!” — Maximus