I'm at Level 30, But I Can Slay Level-9999 Beasts in One Hit! - Chapter 8 Fire God Jade Marrow

Junpei Takeda, a high school student, is childhood friends with Noriko Tatsumiya and is bullied by Kido Shouta. One day, while bullying Junpei, they (Junpei, Tatsumiya, & Shouta) were suddenly summoned to a different world by the whim of “God”. Summoned Heroes with cheats, or so he thought. But it turns out Junpei’s stats were even worse than an average farmer. Tricked into a deathly labyrinth by the only one he trust, he walks the journey for revenge.

“What I want, the Heavens shall not lack! ”

Her original self was a powerful jiangshi who had cultivated for innumerable years. However, when she attempted to unlawfully enter the world of the immortals, she was discovered by the Jade Emperor and thrown into the mortal world as punishment. Her soul then left her corpse, fusing with the body of the Motian Dynasty’s sixth princess. She didn’t even have a chance to fully comprehend her current circumstances before her maid unexpectedly ignored her mistress, even publicly provoking her!

“What? That weak and cowardly idiot who has neither her father’s love or mother’s favor actually mistook her older sister as her maid?! All the royal princes in the world loathe her?”

“Damn you! This old lady will let all of you understand why the flowers are so red!”

“Hey! Did you hear? That cowardly sixth princess unexpectedly snatched away the man that the eldest princess favored today!”

“How is that interesting news? That fourth princess who ran always ran amuck in the capital city is now confined to her bed now!”

The good-for-nothing counterattacks! The previously cowardly and incompetent sixth princess suddenly reveals her exceptional talents! She is full of radiant elegance, and unparalleled disdain!

She is driven by the desire to shed no more tears! However, if she had known what would happen later, she would have been better off acting stupid! She had calculated thousands, tens of thousands of scenarios, but had never calculated one where one day, her own prey would unexpectedly turn around, and ruthlessly bully her instead! Damn it, she still hasn’t sucked any blood yet!

- 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.