Multiverse: Deathstroke - Chapter 525: Sweet-Talking

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.

A bolt of lightning descends from the sky, marking the arrival of a sweet and charming automaton girl in the Marvel universe!She’s adorable, formidable in combat, and capable of even more surprises—uh, ahem!The Marvel Cinematic Universe is rife with danger, but the life of a superhero dedicated to world peace is definitely worth looking forward to!“Waaah! Don’t pull my ears! Let me finish this game! I’ll pay, I’ll pay, okay?!”Although determined to become a superhero, games still need playing, and anime must still be watched!What? You think she’s neglecting her duties?Oh, but she possesses the incredible ability to convert concepts from various works into her own skills!For Kagura Hitomi, who wields the limitless “Conceptual Skill System,” ACG (Anime, Comics, and Games) is her ultimate source of power!

In the post-apocalyptic age, men were damned.

Agent Selene and Agent Helios had always been at each other’s throats, competing as the top agent for the secret organization “Mythos.” But that competition would have to stop as they were suddenly called to cooperate for the hardest mission there ever was.“Agents, both of you have been chosen to work together and go undercover to infiltrate the biggest, most dangerous, and longest-running syndicate there is—Kraken….”“Sounds fun. What will be our cover?”“A married couple.”“Oh, a married—WHAT?!”Having no choice but to put a temporary truce on their feud, they set out to complete the mission. However, when the mysteries started completing themselves like a puzzle, their once friendly rivalry just turned into one hell of a reality. Driven by the ghost of their pasts, they found themselves pointing the gun toward each other.Will they choose the path of revenge draped in cold blood? Will their love be greater than the scream of justice and vengeance? Or perhaps, there’s something more that’s carefully hidden in the dark?