(Couple of thoughts about layer 4) The book scene at the end lends itself to being interpreted as the scene most closely related to the writers' meta-commentary on the FF series in particular and the nature and meaning of fantasy in general. A fantasy story lying on a table in an ordinary world devoid of the mythical/sacred/magical is a relic of an old mythical time, a reminder of the world from which the new world these children and their mother live in came from. The book adds the nuance that the story of XVI does not fully follow the narrative of total secularisation, that after Clive's feat, despite the absence of magic in the hypostasized sense, there is still room for magical ways of thinking, fantasy and imagination (hence the title of the book and the children playing eikons).
Clive, as a chronicler of his own world, by collecting into his compendium the images (eikons) and stories of various great and ordinary people, ultimately leaves as a heritage this piece of "magic" in the form of a fantastic story to the new secular world, thus reinterpreting the very concept of "magic" from hypostasized one -- magic as fireballs -- to a more allegorical -- magic as a fantasy story, as something that exists in the domain of imagination.
(5/?)