The psiwarrior's
psicrystal takes Mage Slayer, Pierce Magical Protection, and Pierce Magical Concealment. It also takes Sunder based feats. It walks up, and sunders whatever is producing a FoM effect (along with other troublesome pieces of equipment). It's Metamorphed into a 12 headed hydra, and has Boots of Speed. So that's at least 13 sunder attempts.
The Psiwarrior himself has EK: Schism, Quicken Power, Practiced Manifester, knows Dispel Psionics, has dipped into cleric for the Inquisition domain, and has a Dispelling Cord. He hits the caster with a couple of Dispels targetting whatever is producing the FoM before he grapples him.
I think I might actually make an anti-mage build now. Then I'll fight myself to the death.
And I don't know about you, but my contingencies usually trigger some kind of teleportation effect... which would fail against this psiwarrior due to the Balhannoth form's Dimension Lock effect. Too bad the radius is so small. I guess we could take Widen Su ability from the Tome of Magic.