(The plot requires changes to the original story, so some characters may be portrayed negatively. If that bothers you, proceed with caution.)
Su Li is an utterly ordinary office worker who unexpectedly binds to a “Villain Reform System.” She's forced to transmigrate into various TV dramas, taking the roles of vicious supporting women, villainous bosses, or disposable pawns who've been flamed online.
System: “Your mission is to change their tragic endings, stop them from ruining themselves, and, while you're at it... save the plot?”
Su Li: “??? You want me to tell Consort Hua to stop acting so domineering? Tell Xuan Nü to stop being so lovesick? Tell Erqing to let go of her obsession??”
System: “Good luck! Fail, and you'll get struck by lightning ^_^”
And so...
“Eternal Love”: As Xuan Nü, she sets fire to the Face-Changing Technique manual. “Sis, skill matters more than looks. Come cultivate with me and build a career!”
“Empresses in the Palace”: As Consort Hua's personal maid, she secretly swaps out the Joyful Fragrance. “Your Highness, the emperor doesn't deserve you. Wouldn't it be more fun to keep a lover?”
“Story of Yanxi Palace”: As Erqing, she kicks Fu Heng to the curb. “Men? Hah! I'm going to be the richest woman in the Qing Dynasty!”
“ Ashes of Love”: As Sui He, she exposes the Empress's conspiracy. “Being lovesick will only make you miserable. Run, sis!”
“The Story of Minglan”: As Mo Lan, she tears up Lin Xiaoniang's script in a rage. “So what if I'm a concubine's daughter? Isn't taking the civil service exams a better idea?”