I Became a Ruined Character in a Dark Fantasy - Chapter 131

She, the prime minister’s daughter, was timid and cowardly. Because her engagement fell through, and her reputation was ruined, she was pressured to spill her own blood in the palace hall! Once again opening her eyes, the cowardice had vanished, replaced by coldness, causing others to be intimidated at first glance. Yet no one realized, she was not her.

The female protagonist of this book is a zombie (probably!) The male protagonist of this book is an air (maybe, but you can’t see it?) The system of this book is a bastard (like to open a mouth too much?) Anyway, this is a story about zombie with a memory, going back to the past, but accidentally turning this book into a story of a savior! (Huh? What? There is a killer? No, believe the author, she really did not kill, really! (No wonder!)

The heroine said: The title of the book and so on are all fake!

- Description from Novelupdates

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.

The heir of a border lord sacrificed his life in battle, hoping to repay the lord’s kindness, but his efforts were in vain.However, when he opened his eyes again…“I’m… the First Prince?”He had taken over the body of the notorious first prince.The only problem… this guy was going to die soon.