Legendary Beast Master: Starting with Contracting SSS Rank Dragon - Chapter 68: You

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.

Alternate Title: Kumo Desu Ga, Nani Ka? - Game SystemElliot? Yeah, he got isekai'd. Bam! Straight into the world of “So I'm a Spider, So What?”. And guess what? He wasn't some puny human or, well, a spider. Nope, he lucked out and got reborn as a freakin' Earth Dragon!But wait, it gets better. Ding! He awakened the 'XX Worlds Game System'. You know what that means? Skills! Skills from all sorts of crazy games!And the kicker? His new neighbor in the sprawling Great Elroe Labyrinth was none other than the little spider gal herself, Kumoko!So, what happens when two totally broken characters end up living next door to each other? They team up, duh! Their genius plan? Hit all the poor monsters in the Labyrinth with a two-pronged attack! A good ol' fashioned sandwich maneuver!But Elliot had a little secret. “Heh, sorry folks,” he probably smirked to himself, “but your boy Elliot here? He's playing with cheats activated!”Skill Acquired! [True Man's Slash]!Skill Acquired! [Skull Splitter]!Skill Acquired! [Planetary Devastation]!

Urano, a bookworm who had finally found a job as a librarian at a university, was sadly killed shortly after graduating from college. She was reborn as the daughter of a soldier in a world where the literacy rate is low and books were scarce. No matter how much she wanted to read, there were no books around. What is a bookworm to do without any books? Make them, of course. Her goal is to become a librarian! So that she may once again live surrounded by books, she must start by making them herself.

Going against the heavens, Tuoba Ye reincarnated. Body concealing Divine Root, hands holding Divine Talisman, possessing previous life’s experiences, from childhood, began cultivating the most difficult body refining method: Mythical Nine Transformations.

- Description from Novelupdates