Three small comments:
(1) I really like that Yona is *not* stupid.
(2) When etherwalking to MC's world, the list of business names visible just inside the building doors on the ground floor make me wonder if we're going to end up meeting characters named Jen, Viv, Eld, Yho, Oonur, or Gilviel!
(3) I find it amusing how often, when a random book is shown, it is identifiably an old Encyclopaedia Britannica volume.