Oh, cool! One of my OCs also lives in the sewers. They should hang out sometime and explore deepest darkest parts of the sewers together. Maybe they'll find something interesting there.
I imagine how they both are going along parallel corridors in the sewers and come to a doorway connecting the two corridors at the same time. And then there is this classic cartoon scene where one character sees another one in a doorway, but the other character copies all his movements, so it looks like it's a mirror not a doorway. XD