How to Tame the Merciless Villain

I transmigrated into the novel called "The Treacherous Sorcerer" as a supporting character who's destined to be killed by Kian, the main villain of the story. According to the original plot, Kian ends up slaughtering every single noble in the empire-including me-so I must do everything in my power to stop him and save myself from an untimely death. Kian has survived a harsh and painful past, so I will spoil him and take good care of him so that he won't turn out to be the vicious supervillain! But what have I gotten myself into? After I rescued Kian from the slave market... he's suddenly obsessed with me!
Will I be able to protect Kian and myself from a disastrous fate?

(Source: POCKET COMICS)

Note: First released in English, with the initial eligible release in Japanese followed by Korean, making it a manga by our standards.