Crossing the Other World to Build Gundam - Chapter 107: Goddess of Justice F-type Gundam and Goddess of Judgment Gundam

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.

Shen Yu's world is facing the apocalypse. With the help of his Gray Mist Space, he could do good things such as saving lives to gain more gray mist and use it to do everything he wants to do. And what's more, no one but him can survive in the Space. However, this time, two figures walk out of the Space, and when they spin around, Shen Yu is shocked, because the two figures are all him from different worlds.“Your world is facing an apocalypse too?”“Indeed.”

At the beginning of the 21st century, twelve reincarnations shattered the void and returned to their hometown.

They preach the world and reopen the space of reincarnation.

Then……

“The Republic of East Asia announced that it will fully implement a five-year spell casting and twelve-year simulation mage training policy.”

“The Republic of East Asia has announced a new change in the marriage law, making it legal to marry someone you call upon after meeting the adulthood conditions of your respective race.”

“The Republic of East Asia announced that the East China Military Region No. 1 Mobile Armor Brigade was established, and the special humanoid mecha “Gundam” officially joined the campaign.”

“Congratulations from the United Kingdom on this, the upper hero Arturia Pendragon will visit Shanghai next month”

“In the far east of Japan, the ignition of the wave engine failed, or seek energy assistance from the East Asian Republic.”

“Space cracks have been discovered in the Chernobyl region, alien creatures have ravaged the Chernobyl region, and the Russian Defense Forces have entered the battle.”

Four years after twelve reincarnators changed the world, Li Ping entered his own battlefield for the first time.

PS: Although the introduction is like this… but in fact it is written about two thorns + machine battle + movie + mythical stew…

- Description from novelbuddy

A civil engineer reincarnated into a magical land and tragically became a Wood, Earth, and Water Sorcerer.While still questioning where his [Earth Bear Bloodline] originated, the Chosen One next door summoned a 'player'...Watching others lead extraordinary lives, Hill just wanted to hide away.