If CIS and PIS are on, Spider-Man loses each fight, the bad guy takes him back to their hideout, ties him up, brags and gloats about their victory. Meanwhile, Spidey uses the additional time to break free from his bindings, catching the bad guy by surprise. A rematch ensues with 'much banter thrown back and forth until the bad guy eventually finds himself hanging upside down on a street lamp while Pete is frantically trying to come up with excuses for why he missed his date.
I'm no expert, but from what I have been gathering, Mirror Master should solo. I am basing this off of other's opinions (which I know I shouldn't, but damn if they weren't convincing,lol), and scans that show how powerful he is. I don't know how he actually loses. PIS/CIS on Spidey all day everyday.