Thanks for the check in, and bummer to hear that Z is leaving.
Personally, I enjoy this RP. I like the characters in it and writing that has occured so far. I would be happy to continue it. I think one option we could use is open up the RP for new players, and explain that we can work them in as associates of our current players (but not pause writing in the meantime). Perhaps even give them some information related to the Outcasts so they bring that to the table over the course of the investigation. Those players could choose to embody one sin, or perhaps they are lesser in that they embody a few in minor ways.