My Pet Beast is Super Fearsome - Chapter 716 - 83 S03 ’Hidden Fang

Mortimer Zhu is an extremely unfortunate high school student who accidentally enrolls into an academy of a dubious nature, where it is the norm to jump in front of moving trains, get dismembered during orientation, and crushed by vindictive bouncing classrooms. Can he stay alive or will he die from the rigors of school? Why have evil spirits suddenly acquired a taste for his flesh?

- Description from Novelupdates

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.

Five years ago, Gu Jiayu, who climbed out of the mountain nest, entered the entertainment circle in order to cultivate, and in order to overcome the shortcomings of emotional gaps, he used an excellent acting skill to hook up a Chinese “little nobleman” abroad. After a month of falling in love and feeling love, he ran away with guilty conscience after the other party proposed marriage.

Five years later, Gu Yingdi had become popular all over the country, but he had a four-year-old son beside him. 

One day, the little handsome guy pointed at the man who took up the entire page in the financial newspaper and said, “Dad, this man looks like me!” Gu Jiayi glanced at the calm, handsome man in a suit and shoes in the newspaper, and asked with a guilty conscience, “He has an onion head, and his body is black and black like the top post. Are you sure you look like him?” That night, “Top Door Post” came to the door … Gu Jiayu, “My son, hide your tail!”

- Description from Novelupdates

In the world of Norse mythology, a human boy falls in love with Waltraute, the fourth Valkyrie sister. He wishes to marry her, but Waltraute gives him an impossible challenge to deter him.

Nevertheless, the boy is determined to carry out the dangerous task and to marry Waltraute afterwards.