Forgot Stone Wall is 3 charges as well...
So we played it out tonight. Good Lawd...
Just a refresher...the party was all on the ledge at the opening to room B21 except the wizard who was above the arrow slit going into B22, he had looked in and saw Marlos and failed his save so he was clinging to the wall turning to stone.
I decided that Larrakh is a 7th level caster and was there meeting with Marlos to talk about the failed attempt to kill the PCs and the destruction of Red Larch along with the Shadow Demon. The party consisted of the following:
Wizard (busy trying to not become a statue)
Paladin (Avenger)
Warlock (Tomepact)
Monk (Shadows)
Cleric (Life)
I admit...I was a bit extra mean...I gave the NPCs advantage on initiative. My reasoning was the NPCs were all aware the party was there and waiting for the fight to start. The party was not so unaware that surprise was warranted, but they certainly were probably taken aback by their wizard screaming in fear and agony as he slowly petrified.
The cleric was up first and opted for bless with a third level slot to give the wizard a better chance on his save vs petrification.
The monsters all went first...the wizard rolled a 2, so he would go last, so that would mean some extra suspense (oh...and we reroll initiative every round because we find that a lot more fun).
Marlos was up first. He walked right through the wall into the main room and used Iron Fang to cast erupting earth (and here I was merciful and didn't give anyone a chance of falling of the ledge). That caught all 4 other characters. The monk escaped damage because evasion.
Larrakh stepped out and hit them with shatter. Doing more damage. Now the Paladin was starting to feel a bit worried with 30 hp of damage right off the bat.
Then the Shadowdemon emerged from the wall, attacked with advantage and rolled a crit. 47 damage to the cleric and down he went...(and that ended bless...uh-oh).
The Paladin was up next. He could have moved closer to the wizard to help him make his save...but that's not his style. He looked the Medusa in the eyes (made his save) and charged, swore his oath of enmity and used smited the crap out of him. I think he did around 50 damage.
The warlock dropped Hunger of Hadar. The monk gave the cleric a potion of greater healing. And then the wizard was up. He needed beat a 14 Con save. He rolled a 13....but has a 12 Con. Just. E. Nuff.
Next round things quieted down a bit as both sides regrouped. Marlos and Larrakh retreated south. The monk shadow stepped into a corner and got a shot at Larrakh with her bow. This broke his concentration on Stoneskin. The Paladin just charged all the way through Hunger of Hadar. Larrakh just grinned at him. The Shadow Demon emerged to attack the paladin and then Larrakh cast Stone Wall, bisecting the room with the Paladin and the Monk on one side with Marlos, Larrakh and the shadow demon and everyone else on the other side.
He could not quite fill the entire space, though so there was a small hole near the top. The monk shadow stepped up to it and then jumped down to attack the shadow demon. The wizard had a scroll of Transmute Rock that he found in the monastery...so he used it to bring the wall down.
The Paladin smited Marlos again and the warlock blasted him. He was down to 43 hp. That was enough. He moved through the wall and sealed the door with Mold Earth and made his escape. No one ever had to make another save because Marlos had to keep backing up out of sight.
So Marlos set about to rallying his forces. Rather than wait to be attacked the party busted through the door. Two Black earth guards opened up on them with crossbows and now a running battle started with nearby NPCs joining the fight every few rounds. First two BEGs. Then three cultists. Then two more BEGs (Yarsha did not join the fight. She was waiting and observing...).
Then a Bullete and a Burrowshark and two hobgoblins (not all the NPCs would leave their posts...they had to assume threats could still come through the front door). The party started getting scattered with the dwarf in the shrine of ogremoch fighting the bullete. The monk and paladin fighting the BEGs in the dining hall and the warlock and wizard supporting both with spells. A fireball took out the hobgoblins and softened up the burrowshark. Now Yarsha decided to act. She felt she could not defeat the party and she wants Miraj dead. So she turned on the one remaining BEG and then brought the roof down on the Bullete with an earth quake spell. This didn't quite kill him but it was enough to convince the party she was on their side.
Once they finished off the Bullette she showed them the way back to the arrow slit that overlooks the front door just as another Bullette and burrow shark entered the Ogremoch shrine. She told them that the mud sorcerer is the real power behind the cult and if they kill him the cult will disband and she told them how to find him. They used their last darkness orb to cover their tracks and Yarsha cast Stone Shape to open the arrow slit enough for them to get out (and she had the monk punch her several times so she could claim to have been defeated with the rest of the guards).
The party fled the complex at that point. Beaten, battered, out of spells and hp. They all agreed this was the closest to death they had come. There was some discussion on what to do next. Go back into the temple to attack the cult before it can reinforce itself, go to the Vale of Dancing Waters to heal in safety (heh!) or turn their attention to one of the other cults and fight Black Earth another day.
All in all, a very fun game. Really touch and go from start to finish.