Not my favorite, but not bad, either. Remember how someone criticized One Graffito Love Note Somethingorother for its manic pixie dreamgirlness - that is, a female lead who has no personality and seems to exist purely to teach the sober main character to embrace life - well, I didn't think it was true of that story, but I see it here. Ofelia has no meaningful arc. She sweeps in, crazies for a bit, and then dies. However, I will grant that this story is redeemed somewhat by the fact that the manic pixie dreamgirl leads the main character to embrace not "life," but rather, "crazy," and a role as one of the universe's protectors.
Or possibly a role as one of the universe's mental patients.
Or - and this is one of the story's other attractive qualities - both, because maybe there's no difference, and that's a thought that sends chills up my spine.
So, not my favorite, primarily because I wish Ofelia had had more agency, but I still have good things to say about it. A solid middle-of-the-road story.