One Piece: I am Imu - Chapter 20: Bartholomew Kuma’s Kingdom

Travel through the world of martial arts, get a god-level kidnapping system, and vow to be the number one kidnapper in the universe.

As long as you don’t want to tie it, there is nothing you can’t tie!

Guo Jing, your daughter has been kidnapped by Lao Tzu. If you don’t want me to do anything to her, you can exchange it with Jiuyin Zhenjing and Eighteen Palms of Subduing Dragon!

What, so obedient?

Then I’ll give you a grandson for free.

…………

Yang Guo, your aunt was kidnapped by Lao Tzu. If she knew the face, she would have cut up her own little penis!

What? Yin Zhiping, do you want to cut too?

Well, I will send you a dragon-slaying knife, cut iron like mud, and guarantee that there will be no pain!

…………

Duan Zhengchun, your wife and daughter have been tied up by Lao Tzu, hurry up and hand over all the martial arts secrets of Yi Yang Finger, Six Meridian Divine Sword, etc., and then kill yourself!

What? Want to have sex with your wives again before you die?

Fuck you, they have been scolded by Lao Tzu “Japanese…

- 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.

“You shouldn’t have crossed this line, Elisha, if you didn’t want it to be like this.”

A sturdy arm wrapped around her swaying body. Her head became hazy and an intentional hot sweet sigh was pulled out of her.

‘How the hell did I get myself in this situation—’

Elisha recalled. This never happened before.

‘Yeah, I remember.’

Her future in which she would become the fake concubine to a demonic man from the same family, and would be eaten to death—even down to her bone marrow. A future in which the Cartier ducal family is embroiled in a power struggle and fragmented.

To avoid that future, Elisha threw herself at Lucerne, the archrival of her former life.

Yeah. There was no problem. She knew this man, before and after her regression. She already knew he was the most notorious maniac in the Empire.

20-year-old Elisha owes 30,000 gold coins (about 15 billion won in Korean currency or around 15 million in USD).

After going back in time, in order to avoid a hellish life because of debt, she becomes the most capable illegitimate child in the world and visits Lucerne, the archenemy of her master.

“What do you want from me?”

“Please lend me some money. And… make me your subordinate. I’ll give you all the information I have.”

“Why should I trust you?”

“I’ll give myself up as collateral.”

Lucerne listened to Elisha and watched her quietly.

“Okay. But I decide how to deal with the collateral.”

“…….”

“First of all, marry me.”

“…… huh?”

Elisha didn’t expect it either. That her information transaction would become a marriage contract.

One of the few self-cultivator who exist in this modern world; due to an unfortunate event, completely destroyed his body in an explosion. Using all his effort to save his primordial spirit, he ended up in an strange magical world and had to start all over again. From a fallen aristocrat to the Warlord of Chaos, this can no longer be summarise as legendary; this is the life of the God of War.

- Description from Novelupdates