I'm the Owner of the Pokémon Day Care In the World of Pokémon - Chapter 1431: A Leisurely Day

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.

He Chuan transmigrated to an alternate world where everyone could reincarnate.

In this world, all citizens who reached 18 years old could acquire a chance to temporarily reincarnate to another world.

They could reincarnate to various worlds such as an Eastern fantasy world, Xianxia world, Western fantasy world, an urban world with advanced martial arts, or even a sci-fi world of the future.

They would acquire a mission along with the ability required to survive in that particular world.

If they successfully completed the mission, they would become a permanent Reincarnator. They could then embark on the journey of being rich and successful.

If they failed the mission, they would become ordinary commoners. The gates to the new worlds would be forever closed to them.

He Chuan reincarnated to his first world.

[You reincarnated into a world of martial arts. You are an orphan and a loser. You awakened the Deduction System.]

He Chuan devoted himself to deducting various kinds of martial arts. He extracted the essence of each technique and merged them into a unique system.

In the end, he became the greatest legend in Jianghu.

[You acquired S rank evaluation. You may choose to keep the power you gained during this reincarnation and use it again in your future reincarnations.]

He Chuan chose to keep the Deduction System decisively.

He then reincarnated to his second world.

[You reincarnated to a fantasy world. You are talented and are the eldest son in the royal family.]

Sit back and enjoy as He Chuan breaks through the limits of the world and crushes the void.

On the day he experienced the most shocking betrayal of his life, as if that wasn't enough, he was beaten half-dead—and that was when the Infinite Wealth System awakened within him.[System Activation Complete!][Congratulations, Jayden Cole. You have been chosen as the Host of the Infinite Wealth System.][Now let’s fix your miserable life!]Thus, the Infinite Wealth System changed his life.The system tasked him with completing many challenging missions—some that could even threaten his life or land him in grave trouble—but the rewards were mighty![Task #002: Buy the most expensive item in a luxury store. Pay in cash. Say, ‘Keep the change.’][Reward: 1 Million Dollars!]---[Task #004: Slap your troublesome landlord with a rent receipt and say, ‘I just bought your building.’][Reward: 5 Million Dollars!]-------[Task #005: Take a beautiful rich lady you never knew to a 5-star hotel and spend one week with her. You must nut her twice or more!][Reward: 20 Million Dollars!]---[Task #007: Attend a luxury auction. Outbid a billionaire on a Rolex and walk away without collecting it.][Reward: 15 Million Dollars!]---As the world’s most dangerous and outrageous missions begin piling up—from dismantling corporations to outwitting billionaires’ most important workers and daughters—one thing becomes clear:Jayden won’t just climb the ladder of success. He’ll set fire to it and build his own throne at the top.Power. Vengeance. Wealth. Women.And one man bold enough to claim them all.