I think we'll see what exactly happens during his thread with Mara!five and whatever he might reveal in the process and go from there. The library is a safer bet. I'm not sure who might be able to repair a book. That's out of Felix's capabilities but the subject can be broached later.

edit: It also occurs to me that Phoebe from the Charmed universe left Felix and the Chimera group a set of crystals. These crystals can be arranged and used to set a trap, as they create a magical cage that keeps in evil creatures. That could be a way to trap him, if need be, assuming the Mara would trigger the crystals.