Ooooooh, I like that. Elaborate, but plausible, I think? It'd be a slow building plot, I think, not just a week long one, or a weekend one though. You'd want to have the shiny-something-or-other to have a chance to thoroughly get around the island. If it was a really slow power sucker, at least at the start, that'd be doable, I think. People, say, wouldn't start noticing their lack of skills/powers for a bit, it'd be gradual.

(And, yes, DRAGON.)