The thing with Raftel reminds me of a book I read a long time ago. It was basically about a boy who wanted to rescue his little sister from a evil sorcerer. It was a really basic fantasy book aside from some moments that I found really interesting back then. Interestingly at some point it had the same quote from Hiluruk. "People die when they are forgotten". By the end the main protagonist was basically was alone in a endless grey void, needing to go to a fortress that possibly nobody had made it to. It wasn't a task of strength at all, rather conviction, about what he truly actually wanted. Only when he made up his mind on what he truly wanted the fortress appeared. It was trippy and scary to read for me and there's a lot more to it than I described, but it was really gripping and fascinating at the same time. By the end the protagonist found a middle ground to his wish. It's probably the only children's book I still care about to this day, lol.
Anyway, basically my theory is actually that the thing blocking of Raftel isn't anything physical at all, rather something like a test of character. I think that would be far more interesting.
Many series do that before the final battle, though, so maybe that's a little dumb? Dunno. Just thought I'd share my thoughts.