This is a simile.
A simile is a comparison using the words "like" or "as."
The thing that happen between chapter 21 and chapter 22 is the tone permanently changes to a more cynical attitude and this is the significant structural shift. The answer to this question is which asking about what happen between chapters 21 and 22 is that the tone permanently changes to a more cynical attitude.
This suggests that the writer belivies, or want to believe, that dragons could be real or were real.
It is a verb because it is an action, something you did.
