Psyborg's Out of the Abyss

You see in your mind an image of Petmailer, his face engulfed by one of the fouls creatures, struggling to breathe.  “Mmmmmmmfffffppphh!  Mmmmmffffppppfffgh!” is what you hear, but the sound in your mind is “Get this thing off of me!  Help!”

Vrah will attempt to make his way towards the sound of Spiderbaits yelling.

Dex Check: 18

 Hopefully once outside he will pull out his Battleaxe and ready an attack.

Readied attack for any of the flying things to come into his 10' range: Attack: 23 Damage: 10

Blinded by the darkness, Phodoxia grits her teeth and, crouching low on the webs, tries to move as quickly as possible towards the sound of Spiderbait's voice.

Dex Check: 18 

If she exits the sphere of magical darkness, either by falling or getting out of it, Phodoxia readies Guiding Bolt to launch at the first darkmantle she sees.

Attack: 11 Damage: 13  

Vrah and Phodoxia manage to find their way out of the darkness without falling in the webs. 

Jimjar crouches low and is looking for the dark mantle that fell. He takes the dodge action and says "I bet this doesn't end well."

Shoowaa is up.

No dark mantles have come out of the darkness yet.

Shoowaa says "I'mma going to be a spider, don't be alarmed."  Shoowaa turns into a giant wolf spider, the telepathing sending out the odd sensation of growing new hair, legs dividing, him growing and other weird sensations.  Shoowaa looks at the darkmantle with his new blindsight, sending the images to the party around him.  He then feels the webs, getting information from that as well.   Shoowaa then moves to underneath the web, still within 10' of a darkmantle.

Vrah shudders involuntarily after sensing the feeling of turning into a spider from Shoowa, then grips his battleaxe even harder.

You hear Derendil growl and lash out into the darkness with his claws trying to hit these creatures. 

Attack: 15 Damage: 5

And here's his DEX save. 19

He actually manages to connect with one of these things and you hear it screech. 

This is its CON save 14

The darkness continues. 

Kisiki is up, then Eldeth, then we're back to the top with Tanis. 

As a reminder, you guys are still sensing Petmailer's panic at not being able to breathe.

Kisiki stumbles as something slams into his shield in the darkness. He lashes his rat's head fetish to his belt (free action), its light not penetrating the magical bubble of shadows, and recites a quick incantation in his native language.

Draconic:

And what happened then? Well, in the Underdark they say that Kisiki's claws grew three sizes that day. And they began dripping venom which would tear apart living flesh, if they connected. primal savagery
Attack: 16 Damage: 1 acid damage

That does hit.

Con save 15

Kisiki manages to slash at the one still flying about in the darkness looking for a victim. It is however able to maintain concentration on the darkness.

Eldeth moves closer to the edge of the darkness and brandishes her hammer, holding an action to attack a darkmantle if one comes out of the darkness.

We are back to the top with Tanis.

Tanis maintains concentration on Hunter's Mark and forces himself to think.  His lanky build has never lent him much ability to grapple creatures away from other creatures with Athletics.  So while he is very cognizant of Petmailer's rising panic through Stool's telepathic spores, he does not think he's the one best suited to blunder into the darkness and try to free the drow.  Nor does he feel optimistic about shooting blindly into the darkness in the direction of his companions.

Instead, Tanis switches to his longbow and takes a few more steps, perhaps 15' further back away from the darkness along the webs, providing more space for others to come out.  He readies an arrow for any darkmantle that becomes visible, including (at higher priority if there are multiple) the one that had fallen away unconscious with the poison.

All this movement in the webs, Sarith and the darkmantle falling... we will likely attract spiders just as Kisiki said.

Since Hunter's Mark grants advantage on Perception to track and find the mark, he tries to peer into the gloom to identify where the fallen darkmantle is and whether it is moving (and in which direction).  Perception at advantage:  25

Tanis spots something fluttering about in the strands below, trying to make it's way back up through the layers of web. 

Tanis will keep an eye on that one below.  Readying his longbow for when it (or any other) darkmantle becomes visible in range.  Which could be right now if the fluttering thing below is within or comes within his 60' darkvision.  Rolling attack with Hunter's Mark but subtract off the 1d6 portion if the attack is against one of the other darkmantles.

Attack: 23 Damage: 9

Vethna grimaces as she senses Petmailer's growing distress. She enters the darkness, moving to his side and attempts to pull the thing wrapped around his head off.
Rolled an 8 for athletics, so not likely going to work...

Yeah, that wasn't enough to dislodge the creature. Petmailer is up and will have advantage on his attempt to break free (assuming that's what he attempts).

Petmailer lifts his arms up and grabs the darkmantle, this time not throwing it, but attempting to grapple it after pulling it off his head.  He has a surge of adrenalin and with the help of Vethna attempts to peel it off his face.  He takes deep breaths, getting a second wind.  (Bonus action second wind for healing).  

Athletics : 25 

Second wind : 11 h.p. healed.

With a desperate effort, Petmailer is able to pull the darkmantle from his head and regain his ability to breathe. He attempts to hold the creature and keep it from attacking others. 

Darkmantle Strength check to break the grapple  8

You have it successfully held and prevent it from making any attacks.

The darkmantle that fell down through the webs has slowly made its way up through the layers of web and is about 20 feet away from the party. It is visible to those party members who are not inside the darkness. 

The other darkmantle inside the darkness (the one that is generating it) swoops back toward Derendil and makes another attack on him Attack: 21 Damage: 7