I have a feeling it would come down to more of Solty fighting Rose. We cannot forget that Solty is...well she's absurdly powerful. Roy would probably be killed instantly, not to mention there's no way he'd be able to kill what remains of his daughter.

There really isn't much to be said about Solty willingly fighting Rose either, but it will probably be one of those 'knock some sense into her' fights. Either that or Rose kills Roy, and Solty avenges him (without killing Rose).

Ahhh, there's still so much we don't know about Solty. The old man in the desert certainly seems to be connected to Solty in some manner.

Two last unanswered questions. Back on the anniversary of his wife's death, Roy left the cemetary as Serika was entering it. Was there any signifigance to that? I hope so. Also, is Solty completely sythetic, as in she was never even a real person to begin with? Or was she given that resemble body as a result of the Blast Fall? If the latter is the case, then I can't help but think that whoever she was is important to the other characters.