Spirit Realm - Chapter 1799: Regretting the Past!

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.

A novel about the Government and its people becoming one to raising their country back up.

A militaristic style novel that implements slight futuristic technology as the plot's basis.

Outer Sect Disciple Chen Yu, assimilates within his body a fiendgod heart.

The heart, is the backbone of life, the human body’s fatal vital point. And it can be said that Chen Yu’s heart is actually his strongest defense point, and permits him to overtake demonic beasts, or divine beasts unlimited potential.

Henceforth, he steps onto the stage and surges forth on a magnificent scale, in a heart-rending mysterious journey.

Talented as a cloud, an unparalleled supreme talent.

10,000 races glorious, cross boundary battles.

Only my heart, eternal!

- Description from Novelupdates

Lin Jiufeng transmigrates to become the Yuhua God Dynasty’s Crown Prince but is dethroned, banished to the Cold Palace, and imprisoned there because he had released the holy maiden of their rival country.

Lin Jiufeng isn’t dejected. He has brought a sign-in system with him when he transmigrated and he would receive rewards when he signs in at different places.

Before the Cold Palace’s gates, he signs in and receives the Ultimate Heaven Slashing Sword Skill!

In the Great Council Hall, he signs in and receives the Heaven Patching Technique!

In the Empress Dowager’s palace, he signs in and receives the God of War Totem!

…

Liu Jiufeng imagines that he can quietly sign in like this until he becomes invincible. Yet who would have imagined that the Heavenly Concubine whom he secretly released would rise in rebellion and seize power after she returns to her country?

After she succeeds, her first priority is to attack the Yuhua God Dynasty to rescue Lin Jiufeng.

When Liu Jiufeng hears of this news, he’s puzzled. «Do I need you to rescue me?»