Interesting options for Vermitrax, I can basically blind the beholder, if I get a lucky roll:
Mirage arcana (Daily Standard Area burst 2 within 10 ✦ Arcane, Implement, Illusion, Nethermancy, psychic, shadow, zone) Wizard 10
The burst creates a zone that lasts until the end of the encounter. The zone is difficult terrain and creatures grant combat advantage while in it. Vermitrax then makes the following attack:
Target: Each creature in the burst
Attack: +11 vs. will
Hit: 2d6+7 psychic damage. Targets are dazed, cannot leave the zone willingly, and cannot see creatures outside it (save ends all). If the target is already dazed, it takes 5 extra damage.