Marriage contract: Genius baby's belly daddy - Chapter 28

Quinn Winter is a young man from another world. One day, he is suddenly chosen to become the new Demon King. But the Demon Kingdom is in big trouble – it's losing a terrible war against the human kingdom called Gran'le.To help his people, Quinn comes up with a risky plan. He will sneak into Gran'le and learn their secrets. But things don’t go as planned. A powerful noble sponsors him, and he ends up joining Heavenward Academy, the top school for training future heroes.At the Academy, there's a big challenge called the Selection. The best students become Paladins – magic knights who fight demons. Quinn doesn’t want to become a Paladin. He is a demon king! But now, he’s stuck in the Selection… and if he wins, he’ll become the very thing he’s supposed to destroy.He started the day badly. Now, things are getting even worse.

The Dancing CorpseKnown as the weakest party in the entire kingdom, they were mocked by others for how pathetic they were.The main character, Adonis, who was supposed to be the plot armor of the story, could barely protect his own harem.That was until Gideon arrived—reincarnated into the story as Adnois himself.But the two were completely different. Why? This new Adonis was blessed with a unique system.He could level up everyone in his party, taking them from a measly F rank to S rank.[You have registered xxxx as your party member.][Current relationship score is 60%; you can only increase from F to C rank.][Improve relationships with key characters to unlock higher ranks.][You can now perform a class change.][You have gained a new skill from leveling up your party members.][You have now unlocked the skill-back system.][For every party member you level up, you gain their skills and talents.]Adonis was now on a journey to build the strongest harem to ever walk the earth.

She never dreamed that she would meet him in the bathroom and they...Five years ago, she betrayed him for some reason and chose someone else, which deeply hurt him and he swore to make her pay the price. After the reunion, he launched a fierce attack on her, while she tried to escape this emotional entanglement.However, the red line of fate seems to have already tightly connected the two. Through repeated interactions and confrontations, they gradually uncovered their past misunderstandings and got to know each other again. His deep affection for her remained, and she was gradually moved by his sincerity.

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.