Suppressing the Protagonist at the Start to Seize the Heroine - Chapter 157

Kawaki, who was born in the dragon vein of a planet (Altana), first met Umibozu who was traveling in the universe, and his girlfriend, Kouka.Later, he came to Earth by accident and met the teacher who affected his life —Yoshida Shouyou.He also met a group of friends. The most conspicuous among the group of friends is a fool with silver hair and naturally curly hair, a short man with purple hair, and a little devil whose catchphrase is “Not Zura, it's Katsura!”Gintama Doujin, not transmigration.

Su Yu, who was attempting to create a second account in the VR trading card game “Yu-Gi-Oh! World Link Online”, inexplicably traveled to the game world, and even had his own NPC identity.Time went back to one month before the game was launched, the nameless Pharaoh was still sleeping in the body of the high school student Yugi Muto, and the Duel City with cross-generational significance had not yet started.When the game was officially launched, players logged in and found that there was a new NPC in the game that was not in the original game.Yuei Vu: Do the players over there want to buy a booster box? Fifty-one packs, five hundred and ten cards, fair price, no cashback!The players stared directly at the Pot of Greed marked as UR in the product list, their eyes were burning, and the same thoughts came into their minds…

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 most successful businessman of his time, who started from being a homeless orphan, died indignantly because of being plotted against by his most trusted aid, his own brother.