Just for background: My player is a solo adventurer with Kendra as a sidekick. He's a Summoner with Eidolons, with a 15 point buy and uses absolutely everything at his disposal to get through the AP where I am not at all kind to him!
And here is what happens....
In Feldgrau, he finds the "dust of sneezing and choking" and pulls a lucky spellcraft roll to identify it.
Having realized Vrood was going to be a pretty serious BBEG, he dimension doors in with his Eidolon in tow ready to die for her cause. She gets her init before Vrood and in fact is the first to move. She sprinkles the dust in the air and one bad Fort save later, Vrood is dead and his jaw is disintegrating with his deathgag just as mine also hits the floor.
Just to make matters even more hilarious, had he passed his save he would have been stunned for about 11 rounds anyway and well out of the fight.
So instead of circle of death wiping out my player like I'd hoped, or eyebite giving them a run for their money, Vrood got 6 seconds of blazing glory where he says "Prepare to die!" and then promptly dies instead.