Though I confess the principal revelation of following the links for me was to be surprised at the various characters Gerard Butler has played without me noting it was the same actor.

It is entirely possible that Christine might make up the other of a pair of scum, with Erik, though I'd guess his victory condition is more likely to revolve around not killing her. That said the Phantom doesn't strike me as likely to have allies and he's usually portrayed sympathetically these days so I wouldn't want to discount the possibility that the Phantom is 3rd party solo or even a NPC, and that we have some other bad guy going on. My VC specifies winning with the cast but doesn't have any sort of attached 'when all the scum die' which isn't universal but is fairly common and that explicit absence leaves the door open for 'cast wins if they survive till round five when the show happens' or 'when Christine is lynched' which would fit the Weber version.

My guess is that Phantom is our bad guy and I don't want us to go tilting at windmills but I think a non-phantom bad guys(s) is a real probability here too.