“How stupid!" said Howl, and began to laugh. At that Calcifer sizzled with laughter too, and they seemed to be friends again. Thinking about it, Abdullah could see how Howl felt. He had been bursting with anger all the time he was a genie, and he was still bursting with anger now, with no one except Calcifer to take it out on. Probably Calcifer felt the same. Both of them had magic that was too powerful to risk being angry with ordinary people.”

Diana Wynne Jones, Castle in the Air

Can I just put out there that the single most brilliant thing that DWJ does is that her characters see each other differently?  HMC is Howl from Sophie’s perspective, and CITA is Howl from Abdullah’s perspective, and they both see him from very different angles.  See, Sophie would never make this^ sort of observation, because she’s not an ordinary person.  And even though some common factors emerge, such as Howl’s cowardice, they appear as new revelations to a new character, and feel both new and familiar to a returning reader.  And that fleshes out not only Howl’s character but also Abdullah’s character because of how he notices things.  It’s just one of those subtle-yet-brilliant things that most writers (and readers) don’t even think about, but then you do start to notice it, and you can’t read anything by Mercedes Lackey anymore because every character either thinks the same or is the exact symmetrical opposite (sorry for picking on Lackey, but I really can’t read Valdemar anymore, and this is why).