Becoming a Wizard by Starting From the Mind Closure Technique - Chapter 56 - Surrender 1

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.

One day, a tower appeared in the skies of all the major cities…

When the enigmatic and overpowered Kieran Drayke awakens in a foreign magical world after a sudden transmigration, he brings along a system unlike any this realm has ever known. The “Sovereign Architect System” doesn’t just make him invincible—it gives him the tools to build something far greater.But Kieran isn’t interested in world domination. At least, not in the usual way.Disillusioned by the world's surface-level glimmer and the rot beneath it, Kieran sets his sights on the forsaken—those discarded by society, lost in the shadows of nobility and corruption. From slums, war zones, and forgotten ruins, he gathers orphan girls of various races—elves, beastkin, humans, and more—each with untapped potential and pain behind their eyes.He trains them in secret. Guides them. Empowers them. Not as soldiers, but as a family. A hidden organization that operates behind the curtains, shaping the world while appearing as ordinary students at the prestigious Aetherion Magic Academy.Kieran himself? Just a carefree, slightly lazy transfer student with a penchant for sweets, sarcasm, and sneaking naps between classes—on the surface, at least.With a slow-burning plot that weaves magical worldbuilding, deep friendships, training arcs, casual comedy, and a cast of unforgettable girls who grow into queens of the unseen, Chronicles of the Hidden Crown explores what happens when an OP MC doesn’t conquer the world with brute force…But builds a legacy from its forgotten pieces.No betrayal. No forced drama. Just the steady rise of a secret kingdom in the shadows of a crumbling empire.