May I please have a link to this Amberverse of yours? (I've toyed with Fiona-as-the-ultimate-puppetmaster theories in my youth!)

Thank you for mentioning Coral and Jurt - I've a really patchy memory of the second set of Amber books.

And, yes, it's a fascinating setting, particularly because of Shadow-walking. Luke was trapped in his own hallucination; what if hallucinations were a part of somebody's disability? Also, since the worlds Amberites "build" are shaped by their perception, what kind of worlds would they find/create if they were, say, blind? [Corwin couldn't manage, but maybe that's because he was using his usual visualisation methods, which I refuse to accept are the only way to Shadow-walk.]