Initiative Breaker
You can survive that first round without initiative if you have the feat Reactive Counterspell. This will let you counter that one nasty transmutation spell that starts an enemy's combo before it starts. Of course, you then need to quicken your first planned spell, or you won't get to use it at all.
Which means you have to plan one step ahead, and count on (if you get the initiative) being able to survive the first few spell you cast negated.
In this situation, you might also try to weather the onslaught: wizards, clerics and druids will wear themselves out of spells (except the evil cleric with harm). You might want to try this:
contingency a teleport to get you out of the situation under a condition or a command word. First chance you get, be able to dispel any teleport wards, zot out of there, and use a crystal ball to start scrying from a safe distance. This might be seen as conceding, but if its everyman for himself, well, I'd rather be the 30th man in the Royal Rumble than the first. Get out of there, conserve your strength, and then come back and nail the survivor.