MMORPG: Rise of the Peerless Pumpkinmancer - Chapter 235: Stable Boy!

On an ordinary day, Lucius stumbled upon a strange, run-down shop. At first, he assumed it was abandoned—until he stepped inside.[You have entered the Universal Alchemy Store.][Congratulations! You are now the store’s owner.][Please craft your first potion.]Lucius blinked. 'What kind of joke is this?' But as if guided by an unseen force, he followed the instructions. Minutes later, his first creation was complete.[Love Potion: The drinker will fall in love with the first person they lay eyes on.]Lucius swallowed hard. 'Wait… does this actually work?'Before he could process it, the shop’s door swung open.Standing in the entrance was no ordinary customer—she was an elf. Long, pointed ears, mesmerizing green eyes, and a body sculpted by the gods. A visitor from another world.A dangerous thought crept into his mind.'Should I test it on her?'

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.

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.

“I can’t do it anymore. Stop it…I can’t take it anymore!” The second young master stopped in his tracks and raised his brows as he stared at Miss Jiang. “All you had to do was jog, so—”

Everyone knew that Miss Jiang was an artiste who had been defamed and blacklisted before she became famous again. When she got into trouble, she did not give up but fought persistently. Everyone knew that the second young master was the mysterious head of the enterprise. He was an extremely cold person with an exquisite taste. Moreover, the second young master had recently adopted a new hobby. He took in his younger brother’s ex-fiancée and he was extremely fond of her…

- Description from Novelupdates