Rebirth of a Nation’s Darling – Prince Charming - Chapter 440 - : Charm beyond gender (1)_1

After dying in an oddly anticlimactic vending machine accident, Kazuki Ren is reincarnated in the demon realm—not as a hero, not as a villain, but as the only human male student enrolled at the mysterious Academy of Ruin, a school where all the professors are demon lords and all the students are powerful, beautiful she-demons.Ren is told he has one task: survive.But there’s a catch. The Academy’s darkest secret is about to awaken, and Ren holds a hidden power that could either destroy the demon world... or rule it.Now surrounded by seductive demons with hidden motives, eldritch tomes, forbidden dungeons, and twisted exams, Ren must master his ability—or be consumed.Magic, mystery, danger, and temptation await in this dark academia harem fantasy.

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.

Civilization is destroyed and records lost. Only Dudian survives in a cryogenic sleep. Three hundred years later, Dudian wakes up and must become Dean to survive. Who can he trust in this world overrun by monsters without and within?

- Description from Novelupdates

Kael was once a being so powerful even the gods feared him—until he was thrown into The Null, a realm of endless torment and eventually cast into inexistence. But he returns, reincarnated as a powerless beggar in a broken world ruled by monsters and corruption.With memory of godly blood on his hands, he is determined to reclaim his strength, survive the Nexus's deadly trials, and tear down the heavens themselves.But it's a matter of time before the gods and celestials know he’s returned. And this time, they will not make the same mistake twice.> ◇ Ravager (Rank E) Eliminated. 20 VRP Gained.> ◇ 0.00109% Memory Unlocked. Forgotten Technique: Blight Shield Relearned.> ◇ Ather'valis, The God-Killing Blade, has been acquired.