Emmet's too old, besides he's still under the employment of Darius. So unless a demon who [i]was[/i] a Casino owner in Kendan is somehow forced to aid the Academy, then it's unlikely I'll have much to do with it with my PCs either. I aimed for Darius to be a part of the Tears do Fall story as well, but likely younger and more naive in that one then this. In this storyline, he'll likely be more serious and cunning with experience at his tail, adding about one more since Kitsune grow a tail (up to nine) for every x amount of years they live. Showing you how very old he is, hell might've had him go down to hellduring that time, maybe a 100 after the events of Tears Do Fall, then reappear in the last fifty or so. 

Olivia's unlikely as she's got no instrument and not showing her powers hinders that. Not to mention Darius's not likely let her out of his sight really.