Seventeen Again: The Sweet Life with My Family - Chapter 656 - : The Huo 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.

“I want to be someone who matters. And I want to know what it feels like to be in love.”Ezra sold his soul to the Storyteller for a chance to live in a world of magic. But Oberyn? - he was cast away from his home, shackled by a destiny he refuses to obey.But destiny isn’t the only force pulling their world apart. A surge of wild magic threatens to unravel everything, and neither can control it. If they want to survive, they’ll have to surrender to something even more dangerous: each other.At first, they’re reluctant allies. Then friends. Then… something neither of them is ready to name.Ezra is plucky, affectionate, and full of heart. Oberyn is proud, aloof, and single-minded in his goals. They couldn’t be more different - until Ezra’s Desire System reveals the one thing Oberyn wants more than anything else.In a world where magic bends to will, control is everything. But when fate ties them together, who will be the first to give in?Genres: Transmigration, System, Magic, Romance, (R-18), boyxboy (bxb)

Lu Zixin has a Black Technology Chat Group of the Ten Thousand Realms , and the group members are the science and technology giants of the world.

Tony Stark : “Group owner, I will send this War Machine Mark II Armor to you!”

Red Queen : “Group owner, do you want to try the latest T virus ?”

Skynet : “Group owner, where is your world? I am going to destroy it.”

Bruce Wayne : “The Batmobile is simply used to pick up girls and today I have a great girl. Do you want to see it ?”

Vega Punk : “Recently synthesized a new demon fruit, does the group want to try an experiment ?”

Little Spidey : “I don’t care, I don’t care, do not send me the red envelope, I will retreat!”

. . .

Lu Zixin : “A group of lawless people, be careful with me!”

- Description from Novelupdates

A young man named Alexander Ashbourne is looking for a job to support his studies. He applies to work as a waiter at a restaurant. The next day on his 18th birthday, a system appears that generates money simply by idling. This system also allows him to trade with beings from other worlds or even visit their realms. Watch as Alexander rises to fame across all the realms.[DeathlessOne: I just spotted this mortal, 'AlexanderTheGrate,' trying to trade his drink called Mountain Dew. I'm thinking of offering my Flame Sword for it.][ShadowEternal: Wait, what’s a Mountain Dew?][TimelessWanderer: Are you seriously considering trading your Emperor-grade sword for a mere drink?][DeathlessOne: It’s not just any drink. The taste is out of this world, It's even better than the heavenly wine.][ShadowEternal: {...}][TimelessWanderer: {...}][Everyone in the chat: {...}][RichNigga: You know what, I’m in. I’ll trade my Gold Deluxe Armor just to see if this Mountain Dew is worth all the hype.]