Maybe it would ring the bell for anyone, memory about it is kind of blurry: Setting - fallout-like world where developed walled area exists - heaven, paradise filled with energy, artifacts, flying transports and stuff and a barren land outside, with scattered lawless and survivors. I think it was about a battlefield of gods and the aftermath from it, which is the current novel's world. Starts with a boy from ruins stumbles upon a rare item that gives supernatural power during encounter with some lawless boss(i think?), shortly after he meets a vigilante girl looking for vengeance for her father from the heaven city, she's had supernatural powers and controlled some flame tools. They embark on a journey for girl's revenge with the promise that she will bring the boy to heaven city. Revenge kind of fails, plot about traitor uncovers. Somewhere in the middle boy loses the girl(i think?) but manages to get to town with a token from the girl. He gets a captain position eventually for one of the groups inside and gets caught up in power struggles, and, eventually, an attempt to change the order, uprising. Plot continues with him working against said uprising and next season he re-starts as a kind of a nameless vigilante/secret agent with a picked up combatant girl, a drunkard-ex hero and some small girl he cared after.