Dice In The Darkness: Cthulhu Calls - Chapter 42: Unforeseen Circumstances

She, a renowned assassin of the 21st century, actually crossed over to become Su Manor’s most useless good-for-nothing Fourth Miss.

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.

This novel is also known as Phoenix Cry Firmament

The previous owner of Mu Ru Yue’s body had been poisoned. Because of this, her meridians were blocked, hindering her cultivation, which eventually led to her being known as trash. After being beaten to death, Mu Ru Yue, who had originally been a successor to a medicinal aristocratic family in Hua Xia, reincarnated into her new body.

They want to seal my path?

I will train to reach the peak of the realms!

They give me a foolish prince as my husband?

I can make do with him.

It would be easier for me to deal with him, rather than with other candidates who would be thrown at me in the future. I shall strive to become powerful enough that nobody will be able to mock or kill me!

- Description from novelupdates

After dying, you wake up and realize you've been reincarnated as a background character who is judged as human trash.The decision to change your destiny comes instantly.Discovering that your identity isn't as simple as you thought, you feel favored by the heavens when you manage to become a powerful character.Katase: You won't fool me. I'll expose you for the pervert you are.Murayama: ...Thank you for saving us.Issei: Motohama, what happened to you? How are you so powerful?Rias: If you join my peerage, I wouldn't mind being yours.Sona: You beat me in the game. That means you're now my fiancé.Yasaka: Honey, Kuno wants a little brother.Kaori Houjou: Shinji-kun, let's go on an adventure.Kaede Kazama: Shinji-kun, thank you for saving me from that ball.Rie Sawada: Shinji-kun, I'll wait for you. You'll be my future husband, fufufufu...Changing known history and taking it in a direction not even his eyes could perceive, he didn't stop no matter what. Not even the other world was safe from his clutches.Lexia Von Arselia: My hero, and my future husband...Shinji advances without stopping.“I, Shinji Motohama, swear here and now that I will reach the top of both worlds.”