Hidden Assassin - Chapter 4

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 countries of Mephius and Garbera have been waging a war for ten years and are trying to put an end to this long fight through a political marriage between the two royal families. Orba, who was driven from his home because of the war and was forced to become a gladiator, looks exactly like the crown prince of Mephius, and it has been decided he will be substituting him during the wedding ceremony. On the other hand, Vileena, the princess of Garbera, has secretly decided to ensnare the crown prince for her own country’s interests.

Su Luo finds himself reborn in the 2013 World Youth Championship, gifted with an extraordinary talent: the Da Luo template, guaranteeing 100% scoring accuracy with every shot!Dominating the tournament and leading the national youth team to the finals, Su Luo's triumph is cut short when he's expelled from the national team for visiting a nightclub. Defiant, Su Luo embraces his rebellious streak, discovering that each nightclub visit awakens new, legendary football skills.[One nightclub visit: Unlocks the Harland template, with unbeatable physical confrontations.][Five nightclub visits: Unlocks the Modric template, ensuring a 100% pass success rate.][Ten nightclub visits: Unlocks the Messi template, perfecting his game to a 100% success rate.]Real Madrid, Bayern Munich, Barcelona, Manchester City, and other football giants fall to their knees before the “Little Prince of the Nightclub.”Guardiola: “Su Luo is top ten in the world when he plays by the rules, but number one when he frequents nightclubs!”Klopp: “Su Luo was seen picking up girls in a nightclub last night? This match is as good as lost.”Wenger: “Come to Arsenal, and you can visit nightclubs every day.”Celebrities like Taylor Swift, Scarlett Johansson, and ElizabethOlsen can't resist his charm: “After last night, he's even stronger!”Desperate, the national team begs for his return: “Su Luo, please come back. We won't restrict you anymore!”Witness the rise of Su Luo, as his nightlife adventures transform him into an unstoppable football legend, reshaping the world of soccer with every visit to the club.Disclaimer: This is Translation

The daughter of a duke, the stuttering Maximilian, married a knight of lowly status at her father’s coercion.