Naruto: Shinobi Payday - Chapter 42: Aftermath

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 protagonist, Winnie (文尼), confesses his love to his childhood friend—the princess he’s been secretly in love with for years—but is brutally rejected in public. His heart shatters, he’s humiliated and ridiculed, and he collapses unconscious. When he wakes up, he vaguely remembers his past life’s memories and realizes he has transmigrated into the world of an otome game he played before. At first, he’s thrilled, thinking, “Nice! I must have been reincarnated as a villainous side character who disrupts the protagonist’s romance, right?” But then… surprise! He’s not just the villain—he’s the “Saintess”!

A mysterious game called “Forsaken” descends upon the world. Players can slay monsters to extend their lifespan, or consume their lifespan to extract game abilities into reality!As extraordinary powers emerge, chaos spreads across Blue Star, plunging the world into disaster.In his previous life, Qin Feng, along with his cousin Qin Xiaoyou, rose to become one of the top hundred global powerhouses. But in the end, he was betrayed by his star-struck sister, who gouged out his 'Ancient God Eyes' to gift them to her idol.Reborn in a new life, Qin Feng chooses to walk alone!His sister? Let her be damned!Thus, a god-level assassin with no shadow or form is born.He is the Shadow, dancing in the dark with his blades. Death and slaughter bloom like art in his hands...Surrounded by countless corpses, he will ascend to the throne of gods!P.S.: Skills evolve infinitely—permanent invisibility, one-hit kill, hundredfold drop rate, divine slaying with ease...