Honestly, I thought the optimized characters would be able to do something like teleport out of the way, turn invisible/blur etc., and do a musical chairs rendition of raise dead to cover themselves, as well as do enough damage to kill him in a few rounds (I thought the damage output of the characters was going to be more in the 1,000 hit point range/round).
I would also think there were possibilities like casting dimension door or plane shift to get rid of the boss (or get the characters out of the way).
I just noticed all the Flame-Spawned creatures have this ability:
Fiery Aura(Ex): Fortitude save DC 21(+3 HD, +0 Racial, +8 Con, +0 Feat)
Anyone within 5 feet of a creature with fiery aura must succeed on a Fortitude save or take heat damage each round from the intense heat. The amount of damage equals the fire damage dealt by the creature's natural attack.
So, if everyone could roll for that if they got too close...
I need to alter a couple of things for this round, I see that I misunderstood Wintersparkles point as CL vs. CR -- so the Troll doesn't have a high enough CL to teleport the boss, and I need to come up with a different way to achieve the same effect -- as well as take into account the AoO.
The idea with the boss is that you have to think creatively to avoid being hit at all, because otherwise it's instant death.