Female lead's Delusion of Starting Over - Chapter 92

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.

I became a side-character who died in anguish because of her good-for-nothing husband.

If I can’t avoid getting married, why don’t I change who I marry instead?

“Excellent, marriage sounds good.”

“Wise choice. Then let’s have a wedding ceremony that isn’t too ceremonious. Following that, I’ll need you to go down to the Fief and behave like the lady of the house until I call for you. Naturally, there won’t be any time to spend in leisure whilst dousing yourself in luxuries.”

“I’m not marrying you, but your father instead.”

“……Pardon?”

“I’m not going to marry you. Do you have a problem with that?”

Liu Qing resigned.

He wrote on the reasons for his resignation:

“I’m going to inherit hundreds of millions of properties.”

- Description from novelbuddy

Orphaned at ten and betrayed by his guardian at nineteen, the protagonist's life spirals into darkness, yet some light remains, only to be cruelly extinguished when his girlfriend sacrifices herself during a brutal demon attack.As a result, he is bestowed with a mysterious system that imbues him with the strength, making him dedicate himself to eradicating demons.Upon defeating the Demon King, he is granted a reward and chooses to reincarnate into a novel-like world with sealed memories until age thirteen.Reborn as the second son of a Duke, he yearns a peaceful life and respite from his tumultuous past. However, fate has different plans.In a world full of political games and supernatural dangers, he finds himself caught in conflicts involving a transmigrator villain and a regressor protagonist.Amid noble family ties, surprising friendships, and veiled threats, he must find his way through this new life, all the while dealing with lingering scars and the chaos that threatens to engulf him and those around him.Can he truly find solace in a world determined to pull him back into the fight?Will he succeed in forging a relaxed and slow life amidst the relentless anomalies at every step?Read to find out!!