I think Murphy is alive in Mirror Mirror. I doubt the Red Court has been destroyed. If that is the case the Titan is still underwater somewhere. I think it's going to be very painful when Harry sees alt-Murphy. Oh, and I think alt-Murphy will be gunning for Harry. Consider that Alt-Harry's friends will likely be Denarians, Necromancers and White Court vampires.
I vaguely remember a WoJ about Mavra being one of Harry's allies in the alt-universe, and something about Molly having become a necromancer with her Proven Guilty boy toy as a thrall. But, I have no idea from when or which event it comes. I could be entirely wrong in my memories, though.
Agreed on him seeing alt-Murphy being painful. I would guess seeing most of his friends in their alternate existences is going to horrify him, though(see the mention of Molly above...). It makes one wonder who he'll be able to turn to. A Dresden novel without anyone for him to play off of wouldn't work so well, after all. Michael seems an obvious choice, if he's alive. There's no telling if Small Favor even happened. The other Knights are also obvious choices, given what they do and who they are.
I'm kind of holding out hope that Morgan is still alive, and we might get some more of him, maybe mirroring Turn Coat with our Harry showing up at his door to plead for help. The two of them have soul gazed. So, it might make for a clever way to prove he isn't that universe's Harry. That said, Morgan still might kill him depending on what he sees, or even before Harry gets a chance to explain...
Mab would make another interesting consult, though not a tag along for the book. Having two Winter Knights in the timeline for a little while might make things a bit... messy. Heck, maybe the other Winter Knight could make a good(and by good I'm not sure I actually mean "good") character for Harry to interact with. I've seen some theories out there that Mab might have chosen Thomas in that timeline. Maybe there's a whole bit where Thomas is having difficulty trying to control the Mantle, and Harry helps him out. Or, more interestingly, the other way around.
Yes, I've descended into rambling.
The obvious most painful option would be Murphy. 'Cause... obvious reasons. I highly doubt she's as in the know if Harry went all dark side. Maybe she's even still working for or in charge of SI?
I... honestly, it's hard to speculate who he'd team up with. I'm still kind of digesting Battle Ground. Though, the wait between books is going to be a pain now that we've just gotten our latest fix.
That's it. I'm going to bed. I'll check back in tomorrow.
