Nope, no sundering weapon, just an oversight in the rules. And heck, we don't know for certain that it was a +5 weapon. It might've been a +1 keen defending glaive of wounding, in which case I could've gotten it.
We actually only hit
him a couple of times. I think his AC was something like 32 (how the heck would he have had an AC in the low 40s, as someone suggested?), and the only times we hit him he was either flanked, or tripped (touch attacks are easy), or he had just charged. Most of the damage was from magic missiles and lightning bolts, honestly. So stop naysaying. Yeah, a really cunning villain would never have come alone if he expected to get beaten on this much, but it still made for a fun fight, and we never complained that the bad guy got away. It will be much more fun when he comes back, maybe in just a couple of days, with a half-dozen allies to lambast us.
I think the only reason monsieur LuYangShih is complaining is because I said he was 20th level, and you think he wasn't played to his full potential. In game, we don't know what level he is. We just knew he was a bad ass who was out to kill us or take us in and then kill us, so we fought back. Plus, goodness, the man could teleport away at will. He wasn't afraid of us.
Right now he's probably slapping himself (in mid-air), realizing he was too confident, and that once he lands and gets himself a new weapon, he'll take us out. Or he'll send lots of henchmen to take us out.
