Ok so here is what Nimu and I were discussing.
We are looking at two spell options.
1. Ulthok and Sirene cast Fire Ball (two 40ft diameter bursts) targetiing side by side. It can do up to 10d6 damage to all inside the burst diameters.
Or
2. Sirene casts wall of fire (the solid bar, it is 20ftx 20ft) contain the Durro on the far side inflicting 2d4 points of damage upon creatures within 10 feet and 1d4 points of damage upon those within 20 feet. In addition, the wall inflicts 2d6 points of damage, plus 1 point of damage per level of the spellcaster, upon any creature passing through it. " Peri would cast Chaos over around #8 causing some those to forget what they are doing.
Valene would cast dispel magic on the ceiling and Frag would cast Grease on the ceiling. That should cause many of the Durro ceiling climbers to fall.
Rayden and Lothor can shoot whom ever they like and the rest perpare for melee against any that survive the drop.

What do you guys think of the these options?