Inside the Cave of Obscenity - Vol 4 Chapter 1: Monster 1

Bathed in the love of her imperial family and her husband, Yun Shang was a spoiled princess and the envy of many at the Royal Court. Her life had been perfect right up till the moment when she realized that everything was just a sham, a ruse designed by the Empress to ruin Yun Shang. After enduring bitter treachery and being poisoned, Yun Shang died with a broken heart and an unfulfilled vow of vengeance. As if God was answering her final request, Yun Shang found herself reborn like an immortal phoenix. She was eight again, and all her memories from her previous life remained intact. The others, however, did not remember the events leading up to her death. Determined not to repeat her mistakes, Yun Shang planned to rain hellfire onto the treacherous, backstabbing villains for all the heart-wrenching pain they had once inflicted upon her. He was the handsome and smart prince of the Ning, who was revered as a battle-hardened general that knew no match in the world. He had thought he wouldn’t settle for anyone until she showed up. A seemingly innocent young princess and a gorgeous prince. Where would their relationship lead them?

- Description from Novelupdates

Escaping from the wedding she dreaded with Crown Prince, Aed Ruad, Princess Anastasia ended up becoming the captive of the Lore's most dangerous man, Prince Ileus.

The notorious imperial court lackey and the meritorious military general were well-known for their mutual dislike, a pair of arch-enemies set in stone. Who could have foreseen the unexpected change in the winds of heaven: the general injured on the battlefield, both legs disabled, and even forced by the emperor to marry his nemesis.  

With one marriage edict, two people with mutual hostility are forced to marry and live under the same roof. Yet after these long days together, they come to the realization that this fellow is not truly devoid of any saving grace/unattainable and high out of reach.

- Description from Novelupdates

In the ruins after the war, the empire is reborn from the ashes.For supreme glory, it competes for supremacy in the world and aims to dominate the globe.