Youth Potion: The Maid's Dark Revenge

Ten years after the queen killed her sister, an alchemist, for refusing a forbidden youth potion, Arya enters the castle a maid. She feeds the vain queen a cursed crimson elixir that rots her beauty and makes her bear a monster, and becomes the king's lost savior with a hallucinogen. At the winter ball the queen rots to ash; Arya dies at her grave.