After Reincarnating as Cannon Fodder, I Was Hounded by the Sickly Young Lady

After transmigrating into the role of a cannon-fodder villain, I got a plot-derailing System.

The System said: Stop Su Qingyuan from turning dark, or die.

I looked at the target of the mission: the cool and elegant eldest daughter of the Su family, who would be betrayed by the male lead, turn into an obsessive yandere, and meet a tragic end.

Then I looked at myself: a cannon-fodder character with the same name as me, whose most famous scene in the original story was splashing red wine on the heroine at a banquet, only to get face-slapped on the spot.

I decided to rewrite the script.

Step one: Pretend to trip at the banquet and interrupt the "hero saves the beauty" scene.

Step two: Approach Su Qingyuan and relentlessly win her favor.

Step three: Ruin every encounter between Gu Yanze and Su Qingyuan.

But...

Why does she look at me more and more strangely every time I get close to her?

Why has she started showing up around me so often?

Why is there something so... terrifying in her eyes when she says, "Don't leave me"?

System, show yourself! Why is the more I derail the plot, the more wrong everything feels?!

[A seemingly aloof but secretly yandere young heiress × a cutie who thinks she's the one doing the conquering, identity reversal, sweet with a sting]