One Piece: A Warlord's Path - Chapter 5: Devil Fruit

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.

Tired of the schemes and strifes of city life, Bei Feng finally returned to his hometown in the countryside

While picking asters ‘neath the Eastern fence;

My gaze upon the Southern mountain rests;

Rearing a few chickens and ducks, I shall lead a simple and leisurely life!

However, who would have thought that fate would play a huge joke on Bei Feng? All kinds of magical items and beings of the Myriad Worlds could actually be fished out of the Ancient Well in his yard!

Even a chicken reeled out of the well ended up chasing Bei Feng all over the yard and beating him black and blue! Speechless and aggrieved, he asked the Heavens: if, that day, he’d fished out a Dragon instead of a chicken, what would’ve happened to him!

- Description from Novelupdates

“An Ice Dragon with a legendary bloodline? Yeah… I tamed it.”Killed in an explosive lab accident, Liu Feng thought his story had ended. But fate had other plans. Reborn in a world where magic reigns and beasts dominate the wilds, science is no longer his weapon —magic is.[DING! You have been reincarnated!][DING! You have received a Talent!][Talent: Eye of the Beast King][Rank: SSS][Abilities: Speak to beasts. Control without bonds. See into their souls. Heal their wounds. Break their will]Gifted with one of the rarest talents in the realm, Liu Feng —now reborn as Aiden Aswald— seemed destined for greatness.But with power came a price: a cruel curse of immortality, one that chained him to an eternity of pain.At twelve, Aiden regained the memories of his past life —and with them, unlocked his beast-controlling powers.His first tamed creature? A terrifying Ice Dragon with a legendary bloodline, feared even among apex predators.Taming it should've been impossible. Surviving it? Even more so.But that was just the beginning.Now, Aiden walks a perilous path, forging bonds with magical beasts while uncovering the truth behind his curse. To break it, he must seek out the Essence of the Chronos Fire Dragon Beast.In a world where beasts rule, contracts are sacred, and survival is earned fang by fang... will Aiden rise as king —or fall as prey?

When he woke up, Zhou Yi became the jailer of the Heavenly Prison.

Fortunately, the fruit of longevity, but there is no way to protect the Tao!

In the chaotic world of the Xiuxian world, monsters and monsters are rampant, and there are many dangers. Zhou Yi decided to hide and practice for hundreds of thousands of years!

The situation is changing, time is passing.

The child who was let go a hundred years ago became the founder of the country.

The young man who was instructed a thousand years ago became the Supreme Elder of the Immortal Sect.

The pet that was raised 10,000 years ago has become an exotic and peerless demon king.

This is the story of a mortal who is immortal, sitting and watching the vicissitudes of life, the change of brokerage, and finally becoming the immortal god of immortality!

- Description from novelbuddy