I Have the Alchemy Emperor in My Head - Chapter 6

The main character has been reincarnated, and he possesses a system and a powerful treasure. Using these, he plans to create his own universe. Keep reading to find out more.

REBORN OF THE LEGENDARY BEAST MASTER

Transform into Divine Dragon and dominate the world!
He is the only Divine Dragon in the sea who founded an underwater Dragon Palace.
With Crawfish Soldiers and Crab Generals as his followers, wild sharks and gigantic octopuses as his subordinates, he is the dragon that rules the city.

- Description from Novelupdates

Mo Chou is the no.1 ranking female assassin in an illusive organization. One day on the way to the organization after completing a mission, she dies. She is shocked when reincarnates into her favorite novel but as a villainess who is the protagonist's step sister and dies a miserable death. She just wants to live a cushy and comfortable life so she decides to completely avoid the red flags aka the main characters and live like a saint (well a saint who is an assassin) But why does she keep stumbling into the main characters especially that infuriating villain and why the heck are they clinging onto her?