I had noticed a lot of Greek terminology and names, such as the nymph Calypso, a name indicating "to keep hidden," from an island called Ogygia who trapped Odysseus for seven years. Also Orion, The Hunter. Also, connections with Alex's fascination with constellations, of which many are named after Greek figures.
I also have a bit of a theory regarding the sacrifice of innocents or loved ones that The Founder indicated. The MC has Polyjuice potion and a Xerox artifact. I get the feeling that someone is going to use the Polyjuice potion to appear as Calypso or Calypso to appear as someone else to hide her (to keep hidden), and the Xerox Artifact will be used to sacrifice someone without actually sacrificing them for real. This would fulfill the entire change of expected events that Idriel keeps bringing up as a coin toss that always comes up heads until the MC states tails for instance. It would be hilarious for Calypso to be captured again only to wind up not actually being the real Calypso while the real Calypso is hidden as someone else and at the MC's side.