((Slow hits all 6 remaining copies, but only 3 of them fail their save.
Tarkus's Sunder destroys the guard's sword.
Nash 1 (flying) casts Haste to dispel the Slow effect.
Nash 2 (in the doorway) backs up and casts Glitterdust on the entire party. Everyone make TWO Will Saves DC 19. If you pass either one of them, the spell doesn't affect you. If you fail both of them, you are
Blinded for 7 rounds.
Nash 3 (flying) casts Grease, targeting Val, Sarm, Quintus, and Suvne. Make a Will save DC 19; if you pass, nothing happens. If you fail, make a Reflex save, DC 18. If you fail that one too, you fall down and need to make a DC 10 Balance check to stand back up.
Nash 4 (flying) casts Fireball on the entire party. First make a Will save DC 19. If you pass, nothing happens. If you fail, make a Reflex save DC 20. If you fail, take 27 nonlethal Fire damage. If you pass, take 13 nonlethal Fire damage.
Nash 5 (in the arena) casts Magic Missile on Quintus. Make a Will save DC 19. If you pass, nothing happens. If you fail, take 12 nonlethal damage.
Nash 6 (in the arena) casts Magic Missile on Val. Make a Will save DC 19. If you pass, nothing happens. If you fail, take 14 nonlethal damage.))
Chaos erupts as the Headmaster's duplicates go to work, slinging magic spells in all directions with reckless abandon and creating a fireworks show that makes the actual tournament battle pale in comparison. By now, the tournament has paused itself, and all eyes are on the battle occurring around the Headmaster's box.
Val, having the original Headmaster in his clutches, headbutts the man for lack of a better option. As soon as the top of his head makes contact, Nash disappears in a wisp of light, leaving Val nonplussed and grasping the air.
Tarkus and Suvne focus on attempting to get the presumably-innocent guard out of harm's way. When Suvne's and Tarkus's pleas fall on deaf ears, Tarkus decides to show the guard he means business, and with one mighty heave shatters the guard's sword into dozens of brittle pieces that clatter all over the floor. The guard takes the hint and flees through the doorway; the copy of Nash standing there deftly steps out of the way for him.
Sarm, having noticed the bracers on Nash light up, targets a pair that one of the other duplicates is wearing, and as the spell does its job, he can sense that the item's powers seem to have been suppressed on all of the copies for the time being - whatever it is. This does nothing to affect how many copies there actually are, however.
Quintus attempts to give his party an advantage by slowing the others to a crawl, but even though it appears to work on some of them, one of the copies has a Haste spell ready to cancel out its effects.
((It's impossible to narrate the effects of all those spell without knowing how you guys do on your saving throws, so feel free to describe those effects in your own words. Round 2 begin!))