Quick Transmigration Cannon Fodder's Record of Counterattacks - Chapter 2766: What Right Do You Have to Look Down on Me?

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.

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.

Ace had always harbored feelings for his childhood friend, only to have his heart shattered when he learned she was secretly in love with Duke. The betrayal left him disheartened, but nothing could have prepared him for what came next.That night, instead of waking up to another ordinary day, he opened his eyes in a completely different world—inside another man's body. Worse still, the first thing he heard upon waking was yet another rejection.Thrown into an unfamiliar land with a past he doesn't remember and a future he never planned for, Ace faces a choice: chase after love once more or embrace a new passion—one that comes in the form of an unexpected farming system. As he cultivates spirit crops and reaps rewards beyond imagination, he begins to wonder: perhaps love isn't found in a person, but in the soil, the growth, and the endless possibilities of the land.Will Ace sow the seeds of a new destiny, or will the echoes of rejection root him in the past?

“Master, the people from the Zhuang family have come to cancel the engagement.”

“My fiancé whose beauty was said to be capable of causing the downfall of a city, finally decided to throw me away?”

“I think so.”

“I want to see this legendary beauty, and confirm whether this bastard is as really great as people said to have no flaws in all 360 degree, a picturesque appearance however you see him; does he need me to help him open the corner of his eyes (Epicanthoplasty) or reshape his chin (Genioplasty)?”

“Actually, he didn’t come.”

“He didn’t? He didn’t even come to cancel the engagement? What a wicked b***h.”

“He definitely will get karma.”

- Description from Novelupdates