... Possible, what I see though is the island separating the Hunger Demon from the very human Thomas ...
I have seen this theory before.
I am
extremely dubious about it.
I think Jim has written some of these
Big Deal(tm) artifacts -- like the Island / the well -- as much more "Big Guns," and not really capable, not really
relevant, to such a fine discrimination as filtering a Whampire Hunger Demon out of a human being. I doubt Alfred would even comprehend the request.
That being said... the dominant Whampire form seems to be Lust, with relatively few feeding from despair or fear. And these Lust demons are profoundly-subject to Love; someone in Love burns them on-contact, and if a proto-Whamp makes love to someone they genuinely love... that burns away the Hunger Demon forever.
And lo, we have Chekhov's
Amoracchius, the Sword of Love.
If Thomas is to be de-Whampired, my bet is on Amoracchius to do the job. Because while an Angel
is a "Big Gun," they're also (very much) capable of the sort of "fine discrimination" that I don't see Demonreach achieving.
And then we'd have a modern Elric (Moorcock's tormented, white, sword-wielding / frail-without-sword guy) ... which could be a bit tempting for Jim... ;-)