Pink ghoul freezes to death.

Tharanau sees the desperate situation and realises that he should not hold back with his magic. He fells the yellow spider and turns to the pile of ghouls. He positions himself so he can shoot at one of them unimpeded (yellow ghoul) and casts witch bolt again (this time second level). (18 to hit for dmg 21)

"Come here and get me!" He shouts at the ghouls.

such voltage was too much for that ghoul and it bursts his flesh killing him instantly.

Quote from Wakharashq >>

from silvery barbs new roll still hits but the damage i not critical so progo gets 5 less damage.

rayce we are counting daigonals as 5-10-5 on the grid, and that gray area is thick web counted as difficult terrain. By my count you cen get with 25 movement do D3 (you could go 5ft. further but that would place you behind goraseth so i stopped there for clear shot)
also by my count then it is 10 from weapon dmg and 5 from sneak - so 15 overall dmg?

tryn who gets the advantage?

 Progo. Got to post later, bot me to speed up if you want, would enter melee or throw dart.

Progo will draw his raiper after taking the fury of blows and taking advantage of what appeared to be a distracted ghoul (despite still making a hard hit).

Striking out at the hurt one:

Attack: 20 Damage: 9 plus 5 sneak damage from having advantage. 

Progo will then start trying to move into the webs (BA: Cunning Action to disengage and move through the webs. "This way you ugly already deads. Someone prep a way to light the webs on fire, after Progo gets through them."

progo kills yellow ghould leaving only one left

Tryn approaches the last ghoul (if possibly into melee, if not disregard the second attack) and stabs it with his dagger before crashing his head against the undead’s.

action: hit 21 for 6 piercing damage
Bonus: hit 18 for 6 bludgeoning damage 

Ghoul tries to claw Tryncaryn as he gets close but is too slow for monks swift moves. (tryn however hits well but the ghoul still stands. Heros turn - Tryncaryn is now at g9

Tryn continues his barrage at the ghoul, sheathes his dagger and opts for a series of kicks.

Attack: 21 for 6 bludgeoning
Bonus: 21 for 7 bludgeoning

ghoul dies. you are free to act. i will post some update on your surroundings later.

Tharanau wipes the sweat of his brow. This was a close call. Too close for comfort. He then looks around the room for treasure from the spiders prey and investigates safety mechanics (for doors etc). He also looks for traps and secret doors. (Investigation 21)

(that might be a bit much to do. Tharanau is actually eager to continue fighting since he still has his bonus HP, which only last 1h)

Goraseth takes a breath "What a splendid fight ! I must say that I have used all I got, I have nothing left in the tank.". He looks at the battleground "I say we look quickly what is in this room, and got get some rest outside. We can com back fresh. Who knows what is waiting for us deeper in this stronghold..."

Action: helping Tharanau investigating

Rayce is thinking these people are very brave but also really reakless.

"Well done everyone, that was an impressive display but it was also really close. I agree with Goraseth, we should rest and return when we have our strength back."

Goraseth gives a nice slap on Rayce shoulder "An old friend of me - sailor in Chult - was always saying:  If the path to what you want seems too easy, then you’re on the wrong path !"

Here you have got the layout of what you have learned about the area. Nothing more than what you saw in spider chamber. there are cauldrons and two chimneys. However there 3 arrow slits that let you see southern part of axeholm.

• Area in gray rectangle is level lower but it has ceiling as high as second level so you can see what is there from your slits. There are still some gathered ghouls that went there when they heard firecrackers. It is the chamber behind these big sturdy doors that you decided not to destroy.
• On the other side you see corridor on the same level as you are and some ghostly figure going back and forth in there.
• Goraseth sees a fireplace that is built into the west wall of this room. Hanging from a hook above its mantelpiece is a nonmagical steel shield bearing the symbol of Axeholm: a dwarven gauntlet clutching a handaxe.The room’s other furnishings — cots, tables, chairs, and empty footlockers — are intact but covered in dust.
• Tharanau is in the room that is thrashed, left behind are wrecked cots, chairs, tables, and other furnishings. A blackened fireplace is set into the east wall. Behind second doors (the ones where Tharanau stands is corridor that is mostly destroyed probably from an earthquake, but there is a dug a winding, rubble-strewn tunnel that is descending. The tunnel is 2 feet wide and 5 feet high. Tharanau hears some ghoul noises from the tunnel but they seem static and not moving right now.

Progo limps around collecting what he can of his arrows, wandering around he finds he down about half his arrows in total. Looking at the ghostly figures, Progo starts pondering how to remove the most safely as he is no shape for a head on assault with so many.

“Goraseth did an amazing job holding off these spiders for so long! I think we should check the doors that lead here and barricade them in some way or find a room inside the fortress for a short rest. You really think we should leave again?” Tryn helps Goraseth and Tharanau to check the place, especially the what he can see from the windows on the southern side. He remembers that the room down was swarming with ghouls before. Perhaps, they could find a way to get them to the front door again and pick them off one by one with the ballista? He relays his idea to his companions and says, “if someone makes noise in the front, like with the fireworks before, and rattle the door, perhaps they’d go there and the rest of us stay inside and shoot ballistas. You think that could work? They seem pretty dumb.”

"To bad Progo doesn't know how to open the front doors to let them out the entry way where the ballista can't miss!"

Seeing the shield Progo woukd like to inspect it for traps:

Perception: 24 (1 less if investigation is the check you want)

If it's clear of seen traps Progo will attempt to take the shield down