Erik Soong's Call of the Netherdeep

Morgan is thoroughly confused, and he can feel his reserves running dangerously low.
But when you hit the bottom… you can still dig.

(Bonus Action: converts 2 Sorcery Points into a 1st-level spell slot.)

He fixes his eyes on the fiend, grimacing.
"Let’s give a shake to that ugly head of yours…"

Morgan casts Mind Sliver on Desu. *(INT Save DC 17 - 9 psychic damage on a failure.)*

Then, unwilling to risk losing concentration on Bless, he retreats farther down the corridor and slips through the first open doorway he can find.

(if permitted under the rules of a free interaction:) As he moves, he lets a healing potion quietly slip from his fingers onto the ground near the west wall, hidden from Desu’s sight.

"Hey, Verin… told you we needed this more than you."
A brief pause.

"Perhaps I was wrong."

DM: Frekor, that is a hit, though it is not enough to destroy the object.

The dagger embeds itself into the chest of the upside down corpse. Desu reels as if struck and almost loses her footing between the tethered pain and the slight swing felt within the room. 

DM: Morgan, Desu barely makes her Save. Happy to let you set down your Healing Potion too.

Morgan can feel Desu throw up mental walls, rebuffing his efforts. Though her eyes are directed toward the center of the room. With the last half a second before Morgan ducks behind the door, he sees that Desu's body language indicates that she plans to make her way toward where her eyes are looking.

Quote from Erik_Soong >>

DM: Frekor, that is a hit, though it is not enough to destroy the object.

The dagger embeds itself into the chest of the upside down corpse. Desu reels as if struck and almost loses her footing between the tethered pain and the slight swing felt within the room.

(OOC: Thank you for the answer Erik. I'll post the entire round now, don't pay attention to my previous post for Frekor, I'll copy that part of his round here so you only need to track 1 post for Frekor's round.)

Frekor seeing Desu struggle more and more to fight each time one of the sacrifices is destroyed, decides to give it a try since he is the closest to the last body.

"Alright. Let's give this a shot" says before droping his scimitar and pulling a dagger fron his lower back. He aims at the corpse and throws the dagger, Hoping it does something against Desu. (Action: First attack: To hit: 9, 2+7. Damage: 6, 2+4.)

Seeing that wasn't enough, Frekor takes from his pouch a second dagger and throws it at the body. (Second attack: To hit: 23, 16+7.  Damage: 7, 3+4.)

The to daggers hit the same spot, making a bigger wound. (Colossus Slayer: 2.)

He then grabbed his scimitar and looked at Desu to see her reaction. (Free action: grabbing the scimitar again.)

"How do you like that?" said with a provoking smile.

(OOC: I'll wait just a little more before putting Hunter's Mark on Desu or the corpse, I only have 1 free use for the day before needing spell slots.)

The two daggers bury themselves into the corpse merged with stone. As the second dagger lands, it is enough to sever some connection between the body and the wall. There is a sound like a heavy stone dropping onto another, then the entire room suddenly drops a foot, causing most everyone to lose their footing and drop to their knees. A sense of unmooring can be felt and the hairs on everyone's neck stands on end. As a rat would know a ship is sinking, so too do you know this room is about to fall off into... something. A grinding can be heard as the single supernatural anchor point remaining, the doorway, struggles to hold the weight of the entire room up and a close inspection would reveal that the room is beginning to slip inch by inch relative to the doorway, toward to a moment where its hold will fail.

Desu is mid-flight to try to intercept the dagger when this happens and rapidly changes course, dropping hard in front of Randa and just out of melee to Frekor (F7)

"You'll never leave this place!" Desu shrieks as she darts her barbed tail at Frekor.

DM: Tail Attack on Frekor: 21 to Attack, 16 Piercing Damage. If you are struck you will be launched 15ft NE to land on C11, on the corner of Thelyss.

Desu then rakes her claws through the air and in that same moment, three fissures are carved open into the floor. Pressurized, superheated acidic air bursts up through the rips in the ground at Nivi, Randa, and Sky. Ylis is out of reach but can feel the heat and hear the release of the pressurized, noxious air.

DM: Nivi, Randa, and Sky. Dexterity Saving Throw please, DC 16 or take 7 Fire Damage and 7 Acid Damage.

IF Frekor takes the hit, Thelyss will stop his flight and attempt to take Frekor's rope from his pouch. If allowed, he will hold one end and leave the other end out for Frekor to grab. "Hold it and whatever you do, don't let go." He will say through labored breath.

If Frekor somehow avoids the hit, Thelyss will think of something else based on what the others will do.

DM: Morgan is in the next cell up, just off the screenshot, which was the closest unlocked door (I went searching in ancient post history to check!). Heroes, go! The first of two rounds before the end!

Randa Dex Save- 13

Randa was scorched and burned, but not down yet.

She turned and Dashed toward the corridor, grasping Ylis by the wrist when she reached the tunnel...

( Assuming she survives the AoO....)