So my crew, that doesn't have a rogue, finally figured out how to get through the locked, living brass doors without making a ton of noise - they cast silence on the cavalier, and let her bash away. One of the two druid also shape-changes into a Rhino and does his thing.
As a result, they mostly snuck into Memrach's chamber. Being shocked by their forced entrance, he was immediately hostile, and wouldn't listen to any diplomacy attempts - didn't help that the character trying to talk to him blew his roll...
He led with his Rain of Debris, and then plunged the room into darkness. The party was able to dispel the darkness and corner him before he could cast any buff spells, so he backed into a corner and fought with his sword. After a protracted whittling down of HP, he finally teleported out.
Needless to say, he's pissed.
I'm fairly certain that once he's had time to heal and buff himself, he's going to be a very nasty opponenet. However, he's also smart, and realizes that he won't be able to beat the entire party all in a head's-up fight. So he's going to want diversions, slealth, and allies.
The party has already mostly laid waste to the contingent of fire giants (all the ones on level D and the hounds are dead - but Gilbans has allied with them), and the lizard-man are also all dead. They haven't entered the palace, and haven't encountered the Flickering Candle (yet).
They brought along an imentesh protean and a Xorn with them from Kakishon. The protean is nursing it's wounds as well, and is looking for some payback. The Xorn is tagging along like a puppy dog, eating any stray metal that crops up (living brass doesn't taste good, and gives him a stomach ache...)
I'm thinking of having Memrach team up with the protean to make life difficult for the group, but I'm having a hard time resovling that meeting in my head. The group has been in Bayt Al-Bazan for 3 days already, so the protean has healed nicely hanging out in the ethereal, but I haven't figured out what else he has been doing.