A Wild Last Boss Appeared - Chapter 187

The legendary mercenary Great Emperor, the “Forbidden God King” Ye Chenfeng, had returned to the city, sweeping away everything with an invincible stance.He had unveiled millennia-old mysteries, Atlantis, the Maya civilization, and the astonishing secrets hidden beneath the Himalayas...

The afterglow of the Middle Ages has not yet dissipated, but the best times have come.

The protagonist travels through Edward VI of the Tudor (duo) dynasty in the 16th century, centralizes power, rebuilds the parliament, and establishes the United Kingdom of Britain. It will take you to experience the most powerful dynasty in Britain, the dawn of the empire on which the sun never sets.

What happens when you transmigrate to Beast World? With the system in hand, the world is for your taking! One day, Su Tang, an intern at the hospital, is struck by a system and transmigrates to Beast World. It's a wondrous world with winged tigers, fire-spitting birds, and enticing man-eating flowers… Everything in this world leaves Su Tang awestruck!After the Chief of Winged Tiger Tribe saves Su Tang, she learns how backward this place was. Su Tang is determined to help change the world! Under the system’s guidance, she helps to extract salt, build homes, dig traps, make weapons and store food for winter… And perhaps even save the world while she's at it!

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.