This was brought up briefly in IRC.  I suggested bounce, but somebody (I can't remember who) one-upped me with Ensnaring Bridge, a suggestion I didn't see in this thread but felt I had to share.  Unless your hand is absolutely stuffed, it should keep Akroma and Spirit away, and depending on how things go might be useful against pristines, exalteds and 5/3's  as well.

I'm at a loss though how to deal with Stax.