Heroic Spirit Deck in Yu-Gi-Oh! - Chapter 633

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.

Hye lived his entire life without a class. After the apocalypse hit the human world, strange creatures invaded and killed humans while new lands were being added.

Systems were given to humans and with the help of the guides, humans started to fight back for their lives. All of this happened under the watch of the venerable beings who were shining stars in the sky; gods!

Hye dreamt his entire life of a chance to prove himself. He was a hard working, earnestly learning and smart youth. However, the apocalypse never was merciful to such humans at all.

Until one day he got a chance to go back in time, when everything started. At this new starting point, he found himself able to finally obtain what he wanted, a class for himself and power beyond imagination.

But will things be this easy for him?

Chen Yan travels between worlds, ending up becoming an honorable prince in a medieval fantasy world. Yet this world was not quite as simple as he thought. Witches with magical powers abound, and fearsome wars between churches and kingdoms rage throughout the land.

Roland, a prince regarded as hopeless by his own father and assigned to the worst fief, spends his time developing a poor and backward town into a strong and modern city, while fighting against his siblings for the throne and absolute control over the kingdom. Join Roland as he befriends and allies with witches and, through fighting and even farming, pushes back invaders coming from the realm of evil.

- Description from Novelupdates

『I’m terribly sorry…』

A god was suddenly prostrating in front of Kayano Takumi. He was apparently killed by mistake. Moreover, he can’t be reborn again. However, he is able to live in a different world? Then, let’s do that, please. The god made a mistake again and transferred me into a dangerous forest. Seriously, what’s going on? Besides, there are children here. I can’t leave them here, I will take care of them.