Hermit Wizard - Chapter 154

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.

When low-level healer Elias Vale stumbles upon a cursed cocoon in a forgotten ruin, the last thing he expects is to hatch the reborn soul of the Demon Queen Revantra—in the form of a scared little girl.To save her from divine execution, she binds herself to him through an ancient soul pact, fusing their fates. Now, Elias is stuck raising the former destroyer of worlds—who can barely tie her shoes, but occasionally melts furniture when she pouts.What starts as reluctant guardianship soon spirals into something far more dangerous. As Rhea (her new alias) grows stronger, older, and far too attached, Elias must keep her identity hidden from zealous church inquisitors, ambitious heroes, and the remnants of her own loyal followers—some of whom want her dead... again.But the longer he protects her, the deeper the bond grows—and the harder it becomes to tell who’s really taming who.Because the world once burned beneath her wings……and this time, she’s not letting him go.

[Cover] NOW HIRING — URGENT — Ghost Story Specialist Corporation Daydream Inc. (Ltd.) Insane Benefits – Come to Work Immediately ※ Note : The company is not liable for any injuries or fatalities that may occur during the course of the employee’s duties. —— A pop-up event for some ‘modern fantasy’ media I loved so much that I even took a precious day off work to attend. On that day, I ended up transmigrating as a character in that very fantasy world. As none other than a newly hired employee at a famous large corporation! A dream job with great benefits, an excellent salary, and even kind and competent bosses. I’m using the information I know about the world to rise through the ranks at lightning speed! Am I happy, you ask? Please, just let me go home. I’m begging you. ※ Note : The genre is horror.

“Elysia, why are you always subtly asking about how Michael's doing?”“Oh? Do I? Maybe it's because he was the only Herrscher in our era who fought for humanity! He was both the First Herrscher and a human named Michael. Yes! That's definitely it!” Facing Mei's question, Ellie just offered a faint smile.“What about Mobius?”“Tch!” The green-haired little girl snorted dismissively, turning her head away.“Who else?” Mei covered her face.“Pardo?”“W-w-what! Kalpas is clearly very concerned about Boss Michael too!”“Get lost!”“Kevin?”“It's not entirely what you think. He has a much more important meaning to us—a family member we promised to walk towards the future with.”-----True Love Warrior Protagonist, Not very Mental stable Protagonist, Pessimistic Protagonist, Anti-Hero Protagonist, Crybaby Protagonist, Michael x Elysia. Oh, Michael... Don't come here; I'm just writing nonsense.