Akuyaku Reijou wa, Hone ni Natte mo Fukushuu shitai!

Original Webtoon https://manga.line.me/product/periodic?id=S142911 The most beautiful noble lady in the kingdom, Sharla, is betrayed by her own sister’s schemes—her engagement to the prince is annulled, and she is ultimately poisoned to death… But her story doesn’t end there. “The prince, my sister, all of them… I will never forgive them!” Reborn as nothing but bones through a mysterious power, the villainess returns to enact her chilling revenge. And thus, the undead noblewoman’s vengeance begins!