Agnyeoneun Molaesigyeleul Doedollinda

Aria Roscent mercilessly bullied her stepsister Mielle and paid the ultimate price for her misdeeds—but not before Mielle revealed that she’d manipulated Aria into harassing Mielle in the first place! Instead of dying, Aria is sent back in time and gifted a strange hourglass with mysterious powers. Now, Aria’s just got one goal: to embrace her role of villainess and utterly destroy Mielle’s life!
(Source: Yen Press)