Affinity: Chaos - Chapter 2000: Battle Frenzy

A story of Gin, a young man who lost his memories before the age of 17 and became a magician. Living a quiet life running a cafe while researching magic, he is suddenly thrust into an unknown world. Moving between Earth and a realm filled with danger and secrets, Gin must rely on his knowledge, skills, and magical prowess to navigate the perils that arise. Ruthless and determined, he will stop at nothing to uncover the truth behind his lost memories and the mysteries of the world, using every tool at his disposal to rise above all

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.

Everyone in the world had transmigrated to an alternate dimension overnight.Everyone here was a lord. They could choose their background and obtain a small yard and three farmers at the start.Lords needed to explore the maps and occupy territories to obtain resources, develop and expand, and conquer monster nests.They had to defend themselves against monster invasions and attacks from various factions to survive.Zong Shen awakened the strategy system at the start.There would be strategic information on everything he saw.The system helped him to find every hidden treasure.[The crooked tree 50 meters southeast of the territory is not as simple as it seems.][You will get a surprise if you walk 35 steps to the front and start digging.][Stop looking, this treasure chest is a trap. The poison gas within will knock you out for three days.]

Wan Tong was bound by the “Corpse Collecting System” and travelled through various small worlds. Her mission is to use the big boss’ white moonlight’s body to resurrect and stop raiders from looting the big boss’ luck.

Wan Tong : Didn’t you say that the big boss has no emotional line?

System : Who brought the white moonlight back to life →_→

Wan Tong : …. sob, sob, every day I try my best to help the boss deal with the raiders, but the boss is thinking about how to attack her!

PS :
(1) The male lead is the same person, the white moonlight is the original MC, which is mentioned later.
(2) Every world is probably sweet love

T/N : white moonlight = first love

- Description from Novelupdates