Cyberpunk: Ultimate Cyborg System - Chapter 128: Mental Exhaustion.

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.

Somebody once told a joke.A man ran in place all his life. He worked a job he didn't love for people he couldn't stand. But at the end of the day, the number in his bank account went up.That man got a second chance at life. He woke up in another world, full of adventures and romances and monsters and gods. And floating above his head he saw the number “1”. So what did he say?“Gosh I better make the number go up.”Not today. Not for this old soul. Reborn as a beast of battle meant to live a short life and die screaming, Garek refuses. He puts the madness of skills and levels behind him and sets out to found a little farmstead. He grows crops. Maybe someday he'll get a pig, and have bacon.It's a shame the world won't let him be. It's a shame that the warmongers and level-grinders hate nothing more than a soul at peace.He put down his sword for a plowshare, but when trouble comes calling, he'll pick it up again.

Zarah is nothing but a lowly runt in Howl Creek who is bullied relentlessly. She wants nothing more than to leave the oppressive pack. When it is revealed who her mate is—none other than her greatest bully, Alpha Damon—she is humiliated and rejected.She leaves for the human sector and lives her life with her son, only for the past to come knocking. Alpha Damon is back, and he wants his son.

“For a long time, we humans have been like the chosen race, without any natural enemies, and have long been at the top of the food chain. Unfortunately, I have to tell you...” “When there is only one bird in a forest, then the forest is basically fake, and the bird was put there by someone...” “No matter how a fish swims, it can never meet any of its kind, which only means that the fish is kept in a fish tank...” “Yes, we are the birds in the forest and the fish in the tank.” “Yes, the world we live in is virtual!”