Toaru Majutsu no Index: New Testament - Volume 16, Chapter 2: Attacking a Base with a High-Class Girl - Tower_of_the_Crystal.

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 youngest, silly fourteenth son of the Yan Emperor had reached the age where he should be given a separated territory now. He rejected the wealthy land, neighbouring the capital city, and instead chose the wildest land in the western region— Liangcheng. Everyone shook their heads and sighed. A fool is indeed a fool. If you go to Liangcheng, you will be killed by barbarians in less than three to five years.

One year later, the watermelon presented to the Emperor as the tribute from Liangcheng in the west was sweet and crispy. There was no one in the palace who did not love it.

Two years later, Liangcheng presented corn as a tribute to the Emperor. The yield was high, and the taste was good. No one in the country could resist liking it.

Three years later, Liangcheng defeated the barbarians and presented their prisoners in front of the imperial court. The people of Yan were excited and their morale was greatly boosted.

Four years later… Everyone said that the fourteenth prince Mingyu was a fool, while the little fatty Yu, who transmigrated with the golden finger, chuckled. Let’s see how you guys look at this fool build his own territory, then.

- Description from Novelupdates

Lu Wuqi was killed while trying to protect a little girl from tens of bullets. But instead of dying, she became the successor of the 'RV upgrade system' and was reborn in a melodramatic post apocalyptic novel and became the scumbag with the same name as her who gave her wife to others to play with to save her life. The scumbag even tried to kill their baby by abandoning her in this world filled with rampant zombies.In the original novel, Lu Wuqi was a vain alpha woman who was even cheating on her wife. she didn't even want to endure the hardships and only wanted to curry favor with the boss of a gang by selling her wife. She wanted to let her wife be the plaything of the whole gang just to enjoy a glass of wine and food. She also felt that their baby daughter was nothing but a burden in the end times and even tried to let her be the food of zombies, this scene was seen by the heroine Yun Qingyue and in a moment of desperation, she awakened superpowers and killed the whole gang as well as the original Lu Wuqi and escaped from there with her daughter.Later, She even met her destined alpha 'Lin Ge' who respected and loved her very much. They even set up their own base and recruited a lot of members and their base also became the only place where omegas could stay safe. Their base also grew larger as they became stronger and they even established their own kingdom after eradicating the zombies.Lu Wuqi couldn't help but feel unfair : qAq... Why am I a scumbag trash.... qAq...Fortunately, Lu Wuqi was an expert mercenary in her previous life and even the boss of her own mercenary agency. Her fighting skills and physical fitness were extremely amazing, coupled with the 'RV upgrade system' , she changed her original destiny written in the novel. She escaped with the cub and the heroine and even made their own magical RV. Later, she slowly regained the trust of the heroine and even grew to love her and their little cub by her whole heart.Lu Wuqi : Hmmphh!! Who said, I was a straight woman?? I obviously Love my wife very much... hehee,........# A little Sneak Peek :Lu Wuqi was currently kneeling on her knees outside their bedroom,Lu Wuqi : Babyyyy~~ I'm Sorry, I will be gentle next time...Yun Qingyue : Shameless!! You always say this....#Another day,Yun Qingyue : I seem to have just seen your dear white moonlight...Lu Wuqi (Scared Jpg.) : Really? I mean... what white moonlight?? I don't have any..Yun Qingyue : With a smile on her face : Really??Lu Wuqi : qAq....THIS IS MY ORIGINAL BOOK!!! READ AND ENJOY...

Master martial artists were beings that no one can obstruct. A martial arts expert has been reborn into the body of a genius whose cultivation has been abolished and has been abandoned by a woman. Therefore, he starts cultivating the art of Xing Yi Quan, producing a solar system within his dantian. His innate talent tramples over all the geniuses, and even the geniuses among geniuses.

His powerful spirit and ruthless and ambitious nature, no matter who he is reborn into, will never change! Slaughter is instinctive, being cold-blooded is his personality, exterminating an entire family is only a means towards a goal, cruelty means infamy, and chasing after women… is just an interest.

- Description from Novelupdates