Sentence:  So while Ralph generally seems to inhabit a different, more glorious and joyful universe than everyone else here his yearning and heartbreak are eminently relateable. Ralph sometimes appears to be a magically demented sprite who has <WSD>assumed</WSD> the form of a boy, but he's never been more poignantly, nakedly, movingly human than he is here. 
Meaning of the word marked with <WSD> tags:  To take on a position, duty or form