@Mike: Two corrections there.
First, humans are the only ones in the Void World able to create and maintain Reasons. The Hitoshura (Nocturne's titular "Demi-Fiend") is half-demon, but that is enough to rule him out as truly human anymore. He can't create a Reason; his incredible abilities, though, mean that the side he backs will likely win.
Second, the Hitoshura did not need to consume others; that was the schtick of the demon shifters created via Atma. Atma shows up in Digital Devil Saga: Avatar Tuner, not Nocturne. :V
And looking back, shit, demi-fiends can't make Reasons. FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF---
Well, that's a dampner to the devil summoner/devil shifter suggestion. Xt
I'd just really rather see an SMT game adapted as one of those "civ game" kind of affairs where you're a leader and can actually direct forces larger than typical party size. The correct term escapes me for the game type...