Counterattack System appeared when I'm already At The Mahayana Realm - Chapter 307 - 306: With enough luck, even a stray dog can become immortal.

In her previous life, she tried her best, she struggled. In the end, she has lost to her own mediocrity.

In this life, she resigned to her fate.

//

After her mother passed away, Xia Rou reincarnated as an orphan and she got taken in by her mother’s lover. Once again she stepped into Cao family, and once again she had to confront the people she loved and hated……

She dares not to expect anything, only except that she won’t suffer any more in this life……

- Description from Novelupdates

Three years ago, when Sovereign Union disbanded, gaming genius Mo Bei laid low and went into seclusion.

Three years later, she returns with a concealed name, disguised as a man.

Despite being scorned and loathed, she ultimately reascends to the thone, causing a sensation in the entire nation!

Handsome but aloof, pursued by countless fans, he was the famous King of the eSports scene.

Dark Flares’ Captain, who was known for his looks, was even more famous for his ambiguous playing style.

*

When she first joined the team, he told her, “Know your place. Do not try to have inordinate ambitions.”

Subsequently, when her identity was exposed, he looked up from his seat at the table and stood up gradually. “Are you thinking of deserting me after marrying me in the game? Hmm?”

Sequel to National School Prince Is A Girl! Mo Bei is the disciple of NSPG’s Almighty Qin. Join him as he too becomes one!

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.

The male student, Fukai Nagamasa, ignores his studies for college entrance exams in favor of following the path to chuunibyou. As he fainted during night cramming session before the exams, he realized that he was transported to a parallel world as a feudal lord in the Sengoku Era. Not to mention that suddenly, he was marrying the sixth Demon King, Oda Nobunaga’s little sister, the one who was purported to be an unrivaled beauty?