MTL - Cultural Invasion In Different World (Cultural Invasion into Isekai) - Chapter 1083 Portal

The first time they meet, she bumps into him. The second time they meet, she agrees to a marriage contract in exchange for his help in her bid for revenge. But… he becomes addicted to loving her.

During his first attempt, he flies a helicopter domineeringly; in his second attempt, he arrogantly removes all his love rivals; in his third attempt, he tries to tie her down using a cute child. Youxuan replies with a plain resounding ‘no’ all three times.

In the end, Shan Hanjie takes one look at her, grits his teeth, and plops onto the ground. “Babe, you dropped your prince charming, please bring him home!”

The world had started doomsday, and I struggled for a year, before I died under an enchanted beast’s claw. Heaven has given me another chance, back a day before the end happen. Will I be able to change my fate, and that of my loved ones? Now, I will start my journey on becoming the strongest on the planet that the Gods have changed into a game world.

- Description from Novelupdates

In the era of interstellar warfare, every melee mech will be paired with a long-range sniper mech to cover the battle.
The sniper mecha master Yan Xueshan (beta) and the melee mecha master Arthur (alpha) are just such a pair. The two have been together for six years.
The upcoming Armageddon is a near-death battle.
the day before.
Yan Xueshan: “Remember to write a suicide note in advance.”
Arthur said frustratedly: “I have only one regret. If I die this time, I will be a virgin until I die.”
Yan Xueshan snorted coldly: “…no promise.”
Arthur asked pitifully, “Master, can you fulfill my dying wish??”
Yan Xueshan: “?”
How absurd.
But Yan Xueshan thought about it, this is his comrade-in-arms, whose life and death intersect, chastity counts as a p- OK, I agreed! !
However, after the Armageddon, none of them died.
Not only did they become war heroes, Arthur also turned into a federal prince.
Arthur took out the marriage application, just one signature, and said honestly and faithfully: “Master, didn’t you say that you will go back to get married and retire after this battle? You help me fulfill my wish, and I will help you fulfill my wish too!”
Yan Xueshan: … something seems to be wrong?

Content tags:
Search keywords: Protagonist: Yan Xueshan, Arthur ┃ Supporting role: ┃ Others:

- 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.