DISCLAIMER: I know what happens here isn't legal, but I allowed it because it was a smart idea and I wanted to reward creative thinking and strategizing.
The party:
Zaigan, Aasimar Synthesist/Hierophant/Archmage
Riddik, Human Cavalier/Marshal
Varren, Human Two-Handed Fighter/Champion
Orion Ocrian Perceval Sullivan (OOPS), Elf Alchemist/Trickster
So this is early in SoV. They've just made it past the lost chapel, and are marching onwards. It doesn't take them long to see and identify the Vescavor swarm ahead. After some brainstorming, they realize they do, in fact, have to go after the queen. So they find the opening. Nobody wants to go in first, so Zaigan calls up an earth elemental to go map the place out. It's a simple map, so I allow it. Here's where things get crazy. They climb down into the caves, and OOPS presents his plan: He'll drink the Spider Climb potion they found a while back, and an Invisibility extract, climb along the ceiling, and drop every last bomb he can make on the queen at once. Knowing the thing has fire resistance 10, I tell him to go ahead and start making stealth checks. He succeeds every last one. He reaches the queen, and starts rolling damage. If the thing didn't have resistance, it would have died three times over. But it did, so it hung on at about 25% HP. Hearing the massive explosion on the other side of the cave, everyone leaps into action. Zaigan casts Haste and teleports the next round, Varren and his Impossible Speed sprint halfway across the cavern, and poor Riddik is just chugging along behind everyone else. Meanwhile, OOPS is running away and trying not to die. He's not doing great at it, and loses about a third of his HP to an AoO. Things carry on, and Varren eventually hits the queen for just under its remaining HP. OOPS is up next, just barely manages to hit it, and it goes down. Swarms disperse, and everyone gets out fine. By far the coolest player strategy I've seen thus far.