I Become a Martial Arts God in the Chaotic Demon World - Chapter 25 - : Discovered?

Draven Noctaris, Lord Of The Vampires, wakes from a thousand-year sleep, ready to rebuild his harem and save his bloodline from a new threat, but the world is not as he remembers.His estate is filled with a bunch of new women, but the world is filled with a bunch of new enemies, some stronger than he could have ever expected.Still, he swears to fix everything and reclaim his spot as strongest in Velhalla. The Noctaris Vampires will rise again, and all will bend to his will. No matter the cost.

Jiang Bai woke up one day and found with shock that he had transmigrated to a parallel world that is similar to Earth. There, he was granted a cheat system to help him forge the path of a tyrant in this new world. He was now stuck in this parallel world body, the body of a weak and cowardly person. Join Jiang Bai as he rose to the top in this new world!

- Description from Novelupdates

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

The second prince has come of age. To celebrate the advent of such an occasion, the search for a suitable bride began. My younger sister was expected to go to the Royal Palace as a candidate. However, despite this, she eloped the day before her departure. I, the older sister she left behind, looked almost exactly like her – so much that we were often mistaken for twins…

One month, right? For just one month, shall I substitute in for my sister?