Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 353

Su Wan is a Realm Destroyer. She shuttles to different time-spaces using the identity of the “Cannon Fodder Ex-Girlfriend”, dedicated to plotting how to happily tear apart the male protagonist and the female protagonist. –There’s no such thing as protagonists who can’t be torn apart, only Ex-Girlfriends who don’t work hard enough~

- Description from Novelupdates

She is an international ace agent,An amazing doctor, God of Assassination, However due to a box she accidentally rebirthed and became an ordinary junior high school student. Weak and incompetent, That scum woman wants to put her head into the toilet. The gambling father, borrowed a lot of money and now they are being chased by loan sharks for debt? There is also a group annoying people in her life. The reborned Yunxiao sneers: I want to know how to write the dead words! She returned from the wind, high-profile attack, if people dared to bully me, they are courting death!

16 years old-- most boys would be falling in love, as their hormones all rise to unprecedented levels. Most boys at Riley's age would have dreams; dreams that will slowly grow into passion. Riley, however, at age 16... killed the world's number 1 superhero.