Ovinrbaane's Powers - auto-dispelling everything?

[Morrigan]

My players are about to face off against Armag. They're level 11 instead of 12, and caster-heavy; bard, wizard, sorcerer, druid & ranger.

I think that Ovinrbaane is going to mince them.

By my reading,the sword auto-casts Dispel Magic on any spell as it hits Armag. At caster lvl 20, it's going to defeat any spell thrown by an 11th level caster on anything other than a natural 1. And I think that would apply even with 12th lvl casters, since it's a d20 + 20 against DC 10 + CL.

Am I reading this right? Is Armag 95% immune to all magic?

[Xenocrat]

I read it as only trying to dispel (once) a spell that is actually affecting it's wielder - meaning one with a duration. It can't try to counterspell an instaneous spell, which has already been successfully cast by the time it hits the target.

So a Fireball or Disintegrate works normally, but a Dominate Person would be subject to dispelling on the sword's initiative count.

[Spatula]

I see it more as the sword will attempt a dispel on Armag every turn on his (or the sword's) turn. So it only impacts spells with a duration.

[Morrigan]

Thanks for the ideas guys - I wound up running the fight using your suggestions but Armag only got hit by one spell in the entire fight anyway, an Apocalyptic Hungry Pit. Which at least ate one of his turns while he undid it. The other casters were mostly busy keeping the Druid alive after Armag took a few Vital Strikes on her or dealing with the bow using skeletal champions. It was the crit-rolling Ranger that managed to take him down.... and then got dominated by Ovinrbaane. Next session ought to be interesting.

Thanks again!