My SSS-Rank Class Is Blood Monarch! - Chapter 209- As Real As It Gets

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.

Lin Fan acquired the Sign-in System that led him on the path of the life of a god-level nouveau riche.

Davies had just been transmigrated… but he wasn’t happy about it.After all, it was now his fifth life, fourth transmigration, the third time he’s been betrayed and murdered, his second…(oh well… no more lines)Davies: Hey! Where are my second and first times…Author: I already said I have no more lines, so shut up and let me finish the synopsis!…After realizing that he wasn’t destined to be a hero and after many run-ins with the “Fated Protagonists”, Davies totally abhors those crybabies that have their heavenly daddies spoon-feeding them with opportunities to be strong, especially at the expense of himself as he always ended up with the short end of the stick in all his lives.Davies is now in his fifth life, and now has a system that seems to target protagonists. Even though he doesn’t understand why he's been used as a steppingstone for the “fated ones” in all of his lives, or why he keeps on transmigrating, or even why the system is just finally showing up after all the transmigrations he’s been true…According to the system, he was on his last life but at least now with the system at his side to aid him against the protagonists, he can wreak havoc and have his revenge against the protagonists in this world and also find out who is messing with his life… is how the story should have gone, but…“What the hell is with this busted system…!!!???”

Fear breaks the boundaries between dreams and reality, and it is impossible to tell which is reality and which is illusory. When the nightmare really comes, no one can be alone.

This is both a danger and an opportunity.

- Description from novelbuddy