The Witch of Greed who died 400 years ago. Her soul resides inside the Dream Citadel within the Sanctuary's Tomb.
Q: What is the difference between 'Artificial Spirits' like Beatrice and Puck, and naturally occurring Great Spirits?
Q: When events occurred that were not inscribed in the Tome of Wisdom (Gospel) Roswaal possessed, how did he interpret them?
### Regarding the contrast between Echidna and Subaru in Arc 4 Echidna's proposed contract was logically the most efficient solution with the minimal statistical casualties. However, it was predicated on completely grinding down Subaru's soul. Subaru refusing her hand was solely because he chose 'foolish stubbornness that refuses to accept anyone's sacrifice' over cold efficiency.
Q: When Echidna offered a contract to Subaru, did she possess any genuine human affection or romantic feelings toward him?
Q: In terms of pure raw mana quantity alone, how does Emilia compare to Roswaal and Echidna?