I think it's safe to say that by this point wel all know that Arcee and Slipstream are unlockable by beating the two campaigns. But I also heard that there are more unlockable characters. Zeta Prime and Deadend have already been revealed (in one of the threads in this subforum), but I heard that Onslaught and Scattorshot are unlockable as well. I have NO idea how to get these 4, though. Does anyone here know how to get these guys, and if there could be more?