Odd would be a meta-aware merchant character who would give hints/tibits about the other romance candidates ("Regulars" as he would call them), as well as sell various items that could help the player advance down certain routes.

If you did decide to romance him (which would take a bit of legwork), he'd let you in on the vulnerabilities/ennui he feels about being in a piece of fiction, and what exactly that means for his existence, but he'd come to be incredibly grateful for the time the player invested in getting to know him despite his initially perceived futility of it all.