He is Lovestruck in the Revenge - Chapter 223 - 216 Join forces to change the fate of Huaqi (One

“Confession Rejection System 1.0: Every time you reject a confession, you become stronger!”

As a weak, helpless and pitiful 3-year-old child, Amamiya Noriko,

In the crisis-ridden world of Conan, he became a kindergarten friend of Kudo Shinichi.

It seems that only by refusing to confess can you live more than a thousand episodes.

Conan: That guy Amamiya is playing with other people’s minds again.

- Description from novelbuddy

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.

After the battle, the beautiful senior sister shyly raised her face in front of you and slowly closed her eyes. At this time, you…

Eh? The choice this time was too simple. Of course, it was four.

Kael was a “rat”—a lowly stable boy in a frozen, brutal medieval world where Knights ruled with iron and Barbarians crushed skulls with bone clubs. His life was worth less than the manure he shoveled. That changed the night he butchered a Knight with a rusty dagger to pay a debt of blood.Chosen by the God of Slaughter, Kael awakens the Aether System. His cheat? The ability to project his soul into other worlds, live countless lives, and bring their powers back to reality—if he survives.But power is not free. It is bought with pain, time, and sanity.World 1: The Wild West. He spends a lifetime as “El Lobo,” a legendary gunslinger. He returns with the muscle memory of a master marksman and a 12-gauge shotgun. World 2: The Martial Arts Realm. He trains for decades as a Wuxia disciple. He returns with internal energy that can shatter steel.Now, as the Kingdom faces war and monsters surge from the dark, the nobles sneer at the servant boy holding a strange metal tube. They chant spells. They draw enchanted swords. Kael takes a slow breath. He racks the slide. Click-clack. “Parry this.”