Streamer in the Omniverse - Chapter 12: Studies and Apocalypse!

Nine Realms Sword Emperor, a legend returns, leveling everything.Genius monsters, trampled underfoot, powerful beings, wiped out with a wave of a hand.If people do not offend me, I will not offend them; if people do offend me, annihilate their entire family.

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.

Lin Xiao, who just won China’s first World trophy, got in an accident and was reborn five years later.

With the rapid development of the eSports industry, the career as professional player bloomed, the Club’s Gods circle/Professional Commentators circle/Popular MCs circle, the old friends from back then were all over the place.

The return of a King, aiming for the League, going from an unknown rookie to once again rising to the top.

Reporter: Regarding the rumours between you and Captain You, is there anything you want to say?
Lin Xiao: With all due respect, with my ability there is no need for un-spoken-rules!
Reporter: Captain You, is there anything you want to add?
You Jing: The rumours are true, back then he was vying for my love.
Lin Xiao: …how many times do I need to say it, that person wasn’t me!

- Description from Novelupdates

His name was 25. On Avalis, he was just one of many tasked with fulfilling missions for Earth’s people. This time, he was given a simple one—live as Zeno Han and have an ordinary life.Easy. Or so he thought.The moment he took over Zeno’s body, someone shoved a script into his hands. “You’ll be perfect for this role!” And just like that, he was on set.[Fame Meter: Unable to Measure. Off the charts.]Doctor? Check. Pilot? Check. Eunuch? …Regrettably, check. Every script forces him to relive past missions, and somehow, he’s nailing every performance. Now, the industry wants to make him a star, but can he still complete his mission? Or will fame—and the terrifying unknown of failure—be his final curtain call?