Thearen has a complicated relationship with the capitol and with humanity in general.
In Firebloods, dragons are capable of shapeshifting into a human form, though it is a learned skill... and a taboo to other dragons, mostly. Humans in the current era aren't really aware of this ability outside of myth, and so a couple of dragons in the story have slipped into human society and live partially or wholly there, for various reasons. Thearen was left in the care of one such person at an early age, taught to shift, and thus raised mostly in human society but always knowing he was not natural to it, that all the people around him would only see him as a feral creature if they knew. He ran away when he was a bit older and has been drifting back and forth between the wilderness and human civilization since then, not quite able to fully integrate into either.
So it's this city in which he was raised, and that capitol building on the hill, where he knows the person who raised him still lives. And that foster parent is someone he both cares for and resents.