New Age Of Summoners - Chapter 2040: Ajax’s Idea

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.

Solver Keter, one of the Five Lunatics of Lawless City, regresses to when he was the illegitimate son of a doomed archery family.“If I regressed and couldn’t even save my family, I might as well go kill myself.”For my family? No, for my freedom!

In the twilight years of the dynasty, treacherous villains rose to power and demons plagued the world.Qin Zheng, bearing a scroll of virtuous deeds, traveled through time and found that by beheading those wrapped in sin, he could attain virtue and enhance his martial arts prowess.Thus, Qin Zheng glanced at the Ghost Head Greatsword in his hand.“The auspicious moment has come, to the execution!”With a great shout, Qin Zheng swung his blade and beheaded his target!!----------------This book is also known as “I've Become an Executioner After Time Travel?” and “Achieving Sainthood Through Merit, I Seek Elevation by Executing Sinners”......

I have given up power that can make the strongest of men tremble. I bore scars very few can imagine; loved women, very few had the gall to talk; and tread paths with chaosfiends.

“And I'm still standing.”

- - -

Gale was summoned into a mysterious world of magic and monsters for no particular reason. Thrown into squabbles of beings vastly higher than him, Gale strived to make a place for himself in the vain dream of immortality and a better world.

That was six years ago.

Beaten and battered from years of brutal war, Gale finally had enough and resolved to start over a new peaceful life in a totally unremarkable town with his trustworthy companion, Vale. Give up the weapon of slaughter and take up a hoe? That seemed like a fine deal to him.

Unfortunately, the valley wasn't as unremarkable as he thought it to be. Dictatorial governing bodies, suspicious practitioners, an exceedingly unwelcoming guest, and a secret that would change the entire world, all impeded his peaceful life. Gale will need all his mental stability to keep his temper in check, lest he brutalises his way out of trouble. Again.