MTL - C-class Hybrids Forced To Slay Dragons - v4 Chapter 56 ask

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.

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.

It always starts with an accident.That’s how all these stories go. One moment, you’re minding your own business, and the next, you wake up in someone else’s body. For Caspian, his accident started earlier than he even knew.Maybe it began when his sister got him into romance novels? Or when he started really sympathizing with the villains at the ends of books? He’d never know. It was too late to worry about it now.For now, he had to find a way to fix this nightmare, or rehabilitate his image, all while trying to free himself from the fate set out for him. All because of the damn “gods” who he'd cut a deal with.These were the only two options he had available, and he wasn’t sure he could succeed at either. The man he had taken over for had been…a true piece of work. And the secret villain of the book he had been reading before he passed.It had been a harem novel. A reverse harem novel.He was trapped in a huge ass CASTLE with a bunch of men who hated him because he was taking affection and time away from their shared wife. All Cass wanted to do was be a good person, not mess around with this poor woman and her far too handsome husbands.But why would no one leave him alone? Was he too suspicious? And why, after going out of his way to avoid them like they had asked, did they keep pestering him?And where did the heroine go?How was he going to manage three, handsome men without the heroine?

The beautiful neighbor he had known for about half a year suddenly asked him if he wanted to be together.Liu Xin'an considered for a brief few seconds before nodding with a smile.But a few days later, she disappeared without a trace.Late, she reappeared on television.Liu Xin'an: So the girlfriend I liked turned out to be a big-time celebrity?