Monsters Are Coming - Chapter 935 - 261: One Million Qualifications, Strange Homeland

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 must entertain the masses.’ This was Jester’s lifelong goal.After leading 12 different lives as a Hero, King, Sage, Jester, and more, all he wanted was to mock the king and his court.Unfortunately for him, his majesty didn’t appreciate his vicious jokes.Jester died, trying to flee for his life. But death wasn’t the end for him.For his 13th and last life, he triggered the Archetype System and reincarnated in a world of magic and perils.[This is your last life. Don’t waste it!][Welcome to the world of Archetypes!]Oh, before I forget, soon, players from Earth would flood into his new world.But even players won't escape from his clutches! Even people from the Earth will be tamed!

Tired of the schemes and strifes of city life, Bei Feng finally returned to his hometown in the countryside

While picking asters ‘neath the Eastern fence;

My gaze upon the Southern mountain rests;

Rearing a few chickens and ducks, I shall lead a simple and leisurely life!

However, who would have thought that fate would play a huge joke on Bei Feng? All kinds of magical items and beings of the Myriad Worlds could actually be fished out of the Ancient Well in his yard!

Even a chicken reeled out of the well ended up chasing Bei Feng all over the yard and beating him black and blue! Speechless and aggrieved, he asked the Heavens: if, that day, he’d fished out a Dragon instead of a chicken, what would’ve happened to him!

- Description from Novelupdates

This crossing is so strange, death crossing, game crossing, etc. are probably barely acceptable, but why can you cross even if the fish tank is broken?

and actually passed through the magic tree in “OVERLORD” that is said to be able to destroy the world?

No! It is sad enough to regenerate into a plant. The protagonist, Ainz Ur Gong, the undead king, has also accepted the adventurer’s guild mission and wants to kill me!

I want to change my destiny! Live! I want to-surrender!

Ainz: Since he has accepted the job commission from the Adventurer’s Guild, deliberate failure is detrimental to the prestige of Ainz Ul Christine (the “surrender” button has been deducted)

actually died as soon as he crossed, but there is still a chance to return~ from the beginning of the magic tree to this world.

I must change my destiny this time! Live!

- Description from novelbuddy