I Died and Became the Villain's White Moonlight

Sang Nian's mission was simple: marry the villain, break his heart, then die by his hand. She nailed the dying part—just not the way she planned. Reborn three centuries later, she discovers the man she tormented has become a world-ending demon lord who tore through hell itself searching for her corpse. Now the system wants her to redeem him and teach him love. There's just one problem: he still thinks he hates her. And she's terrified of what he'll do when he realizes his 'white moonlight' is back from the dead.