Only one person participated in the event across both sites. Their question is: "I don't remember if this was explained, but I will ask: was the "Gluttony" factor mentioned by the sect that summoned Cain really implanted in him? I think he just eats a lot because he consumes a lot of energy too."
Aight, so non-spoiler answer: The Gluttony aspect was implanted into his soul and is much more broad in terms of use. Just think of it stacking w/ Cain's normal gluttony.
The spoiler answer is attached to this paragraph as a comment. Seriously, don't open it if you don't like spoilers as it is beyond massive. Also keep your non-spoiler reactions and comments to the previous paragraph and spoiler ones here. I will be monitoring this chap heavily to enforce it.