What is this I don't even-- part the whatever

Have finished Onmyouji 10, in which Seimei states several times that he's a swallow who's invaded the Dragon King's underwater palace to steal a jewel. This, to my ears, is too reminiscent of Peter Pan:

"Pan, who and what art thou?" [Hook] cried huskily.
"I'm youth, I'm joy," Peter answered at a venture, "I'm a little bird that has broken out of the egg." This, of course, was nonsense; but it was proof to the unhappy Hook that Peter did not know in the least who or what he was, which is the very pinnacle of good form.

Seimei has excellent form, but no sense. IIRC (If I'm Reading Correctly) at one point he has a snit fit because he was compelled (but what compelled him?) to make a declaration (to the empty night sky) that he's proud of being a human being and happy to have been born. This is somehow a blow to his dignity. Possibly because he's really a swallow.

Or maybe it's just that he *might* become a swallow. OTOH he might become a (tinkling) brass cymbal, with markings, that's confusingly called a mirror. Whatever, at book's end he has a honking big 'jewel' that looks like a bowling ball, which he gives to Murasaki Sue. Whose name means 'true kudzu'-- yes, the invasive vine that ate the American South. How appropriate. (And now I can't find the Japanese word for girlfriends who move into their boyfriends' apartments uninvited and take over the housework and laundry and whatever. My life is full of woe.)
( Further thoughts on my woeful lot )