Agreed, having the summoned character replace your party is an incredibly stupid idea. Remember how summons work? They show up, do a ton of damage, then vanish. They don't show up, make the rest of your party go away, throw a toothpick in the general direction that an enemy might be in, then kick around doing not very much. It needs to be a one shot thing that has an incredibly high cost but the potential to really equalize strong enemies. Like a Super Desperation Move in KOF. Actually, it should be like Kyosuke's Final Remix in CvS2. If you get tapped with his foot, you get ganged up on in a BIG way.