|Synthesis Category||Mystery, Fuel|
|Monster Drop||Twilight Maiden, Void Maiden, Hell Maiden, Eternity Goddess|
- "A mystical substance said to influence one's lifespan. It exists in every organism, and its pulsating rhythm is what supports each life."
- — Atelier Meruru description
After 10/1 of Year 4, an event will take place where Astrid will ask Meruru to recreate the Potion of Youth after she breaks the phial of liquid. In order to create the Potion, it needs the unique and rare Abyssal Soul required from a demon within the Endless Corridor. Meruru's task will be to defeat the demon and retrieve the Abyssal Soul.
By defeating the Twilight Maiden deep within the corridor, Meruru can obtain the Abyssal Soul and finally create the Potion of Youth. Aside from creating the potion, the Abyssal Soul can be used to create powerful weapons and armor.