Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 424

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 daughter Xu Youyou, whom the Xu family sent to the countryside to recuperate many years ago, has returned to fulfill her engagement with the Lin family.

On the eve of the wedding, the groom escaped from marriage and went abroad to find his Bai Yueguang, everyone: wow… [eat melon expression]

Xu Youyou: Oh huh.

In the next second, the white and soft little hand grabbed the man’s sleeve, and said in a sweet and glutinous tone, “Mr. Mo, can you marry me?”

…

Mo Shenbai is a pure-hearted, mysterious and low-key business tycoon. He has been in the elusive shopping mall for ten years. No newspapers and magazines dare to publish a photo of him, and there is not a single strange person who can let him take a look.

Everyone said that Mo Shenbai’s marriage to Xu Youyou must be an agreed marriage, and they will definitely divorce after one year.

Xu Youyou ate her melon with gusto, but just when she was eating, she realized that something was wrong.

No need to pay for shopping, no need to order food, no matter where you go, everyone greets her warmly: Mrs. Mo is good.

Later, the dark and white Bai Yueguang came back, and the ex-fiancé expressed affectionately: “Yoyo, only I really love you, come back to me, I don’t despise you.”

Before Xu Youyou could answer the man’s domineering embrace, her low voice was sexy and sultry: “Baby, you didn’t tell him, here is the crystallization of our love.” Her warm big palm pressed against her flat belly.

Xu Youyou blushed, and the scumbag blushed…

[Brainless Mary Sue loves text after marriage | Focus on male abuse two]

- Description from novelbuddy

In the depths of a newborn universe, a cultivator takes advantage of the abundant energy to refine himself a treasure. But after 14 billion years of refining and quite a few more to go, he decides to entertain himself by releasing countless systems and watching how the creatures of this fledgling universe handle them.

On Earth, a young man, lost and confused about what to do with his life, sits in a park and looks up at the night sky. A shooting star, a wish and a bang. When the boy finally wakes up he hears a sound, "assimilation complete. Launching System. Welcome to the Midnight Inn. Host Designation: The Innkeeper."

‘I want to travel to a place unknown to the many…’

It was a passing wish to the weary and tired Eugene and she’d not think it’d ever come to pass… but it did.

She opened her eyes and found she was sent to a novel-like world she wrote in passing and became Jin Anika, the scorned queen notorious for her ruthlessness and undeserving of her status.

Queen Jin only sought and desired to see the destruction of this world — the villainess who met her untimely and miserable end at the hands of her husband, Kasser, the reigning king of the Fourth Kingdom.

While struggling to survive in the unknown world, King Kasser visited Eugene and demanded that a contract be fulfilled and come to fruition.

“Three years ago, we made a deal.”

It turns out the Queen was under a contractual marriage with King Kasser. The ultimate price? To bear him a child.

“A… a child?”

“Yes, my successor.”