The Dragons of Babel
From the publisher:
A war-dragon of Babel crashes in the idyllic fields of a post-industrialized Faerie and, dragging himself into the nearest village, declares himself king and makes young Will his lieutenant. Nightly, he crawls inside the young fey’s brain to get a measure of what his subjects think. Forced out of his village, Will travels with female centaur soldiers, witnesses the violent clash of giants, and acquires a surrogate daughter, Esme, who has no knowledge of the past and may be immortal.
Evacuated to the Tower of Babel–infinitely high, infinitely vulgar, very much like New York City–Will meets the confidence trickster Nat Whilk. Inside the Dread Tower, Will becomes a hero to the homeless living in the tunnels under the city, rises as an underling to a haint politician, meets his one true love–a high-elven woman he dare not aspire to.