As described, this is an interesting format: a short story, together with a lot more information which, between the "Letter to the Reader" and early draft, provides a much stronger and more detailed context to the entity of the title. The story's worth a read in a general YA-fantasy sort of style. On a gaming site, I should mention that no game stats are included, but the extras easily provide the kind and quality of information a GM would need to derive stats for any chosen game system - so it's almost like a systemless game supplement in that regard.