We had our final fight last Friday, with me as the Spider Queen overlord. The heroes were:

Verykas with Taunt, Cleave, Leadership, and ironskin from the Hunting the Wyrm rumor.
Silhouette with Cautious, Acrobat, and the Soul Shadow familiar
Lord Hawthorne with Knight, Unmovable, and Weapon Master.
Battlemage Jaes with Inner Fire, Blessing, and Wind Pact.

The first four levels went fairly normally. I managed to destroy Verykas's gold shield with a Crushing Blow, which would give me a chance to actually hurt him in the final fight. I also stopped a gold spear with a Dark Relic, which forced Lord Hawthorne to suicide so he could get rid of the Black Ring.

In the final level they started off separated, and that gave me a chance to drag things out for a while, repeatedly killing Lord Hawthorne. He did massive damage and had four attacks per round, but was a glass cannon so every time I spawned monsters they killed him. I also got lucky and redrew the Crushing Blow, taking out Verykas's armor (though he was able to replace it with some weaker backup armor they already had). When the final battle started I was at 140 health thanks to all the deaths and the Toughened upgrade. The heroes had around +12 health each IIRC.

I lasted one round.

The final fight makes it the Spider Queen's turn immediately, ruining their plans for a full frontal assault. Jaes took his guard action and hit me pretty hard. I returned fire by moving the webbing to hit everyone. A fairly average roll ended up doing a little damage to two characters and healing me some via Spirit Drain, though not all the way to full. Lord Hawthorne's four attacks were unstoppable. He had a morning star and the bloody dagger, and at the end of it I was both at negative health and had 4 bleed tokens waiting to finish me off on the odd chance I'd survived.

It was a great campaign despite that, and we'll be starting Sea of Blood soon. Even though I knew I was going to lose since I'd chosen not to try for a Tamalir stampede, I'd do it again. I'd probably pick a different avatar next time as the Titan or Beastman Lord fit my style better, but Slaggaroth was most definitely a beating waiting to happen. I'm looking forward to Sea of Blood and a lack of things like Knight and Unmovable. I'll be on the hero side this time.