Apparently my "I have some surprises of my own" was to miss the same PC with
13 out of 14 attacks. Yes, that's right, folks; I needed a 10 to hit, and missed the same PC 13 out of 14 times.
Nothing makes a solo monster angrier than that.
There was one death, one of the best deaths I've seen in D&D, but I'll let Sagiro tell you about it.
I modified the bloodkiss beholder as followed (I'm not including full stats, because it's still alive. I don't mind talking about what I removed, though):
Blood Call (minor, recharge 56): Ranged 5; targets a bloodied enemy; +11 vs Will; the target is stunned (save ends). Aftereffect: The target is slowed (save ends)
became
Blood Call (minor, recharge 56): Ranged 5; targets a bloodied enemy; +11 vs Will; the target is pulled two squares and is slowed (save ends).
I'm not a huge fan of stuns; I don't want PCs to feel completely helpless when they get eaten by monsters, especially in this tough a fight. I also completely removed the Bloodkiss power Elric just mentioned. I don't mind solos healing when appropriate, but that wasn't a feel I wanted for this fight, and weakness effects just annoy me.