Grugga snarls his challenge and the three sewerfolk facing him weaken in their resolve [none of them can possibly make that save].  All three use their reactions to move away 5' from Grugga but they do not let him pass.

[Grugga can move 15' west now if he likes.]

Aubrey has the guard to the right back on his heels, first shoving him back 5' [round one], then hitting him with the first of his two eldritch beams, then shoving him back another 5'.  He glances over his shoulder at the howling darkness he is being propelled toward.  [The right guard is now 2 squares further to the right.]

“Well aren’t you full of surprises.” Cosette pops a brow with a smirk as she’d squeeze by Aubrey to peek through the barricade and down the hallway. “Mind yer ears boys!” She’d bring her fingers to her lips and lets out a sharp whistle. Focusing the sound, she sends it down the corridor, pinpointing the three individuals and their barricade blocking Rohu’s path. A sudden loud ringing noise, painfully intense, erupts amongst them. 

Casting Shatter lvl 2: 17 Con ST DC15 

A high-pitched, ringing whine rises among the three sewerfolk in front of Rohuzar and Grugga.  Two of them clutch their ears in agony, while the third grimaces but retains his composure.

Rd 2...

     Raqisat trades his whips for his swords and attempts to go to town on the rat-chump just south of him.

Reckless Scimitar Attack:  11 to hit, 5 damage...

Reckless Bonus Action Scimitar Attack:  20 to hit, 7 damage...

Raqisat, the sewerfolk are rousing from their surprise, and this one parries your first attack easily as he draws his own short sword.  Your second slash come in below his defenses, however, cutting right across both of his elbows.  But it is as though you dragged a butter knife across his skin instead of a sharpened blade.  There is no wound and he sneers back at you with knowing, beady little eyes.

The young noble was not unaware that most people would find some of the powers of his taliman a bit...unsettling, so he fires a quick grateful smile at the confident bard as she squeezes past him, hoping the others to would be as open minded with the magic he called upon, seeing it was only necessary means to a good end. He then momentarily covers his ears as Cosette's spell blasts the sewerfolk down to the left, giving her an appreciative nod at her impactful show. "You really give your audience a performance they deserve Ms. Cosette." He adds with a playful smile.

Leelan covers his ears as Cosette cast her shatter spell. Considering how crowded the hallway is, he is hesitant to fire an arrow and possibly hit one of his comrades (again). As such he will make way for everyone that hasn’t moved out the corridor yet and he will hold his action until he gets a clear shot on one of the sewerfolk.

Rohuzar has his eyes forward, and runs down the hall to try to finish off the guards Cosette has scattered with magic. His silver sword swings hard with a cross slash to deal with these rat people

Attack: 22 Damage: 9 

Attack: 21 Damage: 9 

One of the guards by the door - the same ineffectively slashed by Raqisat - is able to take an attack of opportunity at Rohuzar as he moves past him down the hall.

Shortsword - Attack: 6 Damage: 5

Ignoring the attack, Rohuzar races down the hall, standing beside Grugga.  He viciously cuts down one of the sewerfolk with his silver sword.

The attack on Rohuzar clatters against his armor, jarring the shortsword out of the guard's hand and down to the floor.

Two sewerfolk remain at the end of the tunnel facing Rohuzar and Grugga.  One seems prepared to run... but the other glares at him.  "Stand!  Remy went to warn Elton."  He looks back toward Grugga.  "For the clan!"

The sewerfolk undergoes a monstrous transformation, his limbs contorting and fingers lengthening, and the patchy beard and body hair erupting out into a pelt of matted grey fur.  Within seconds, he has shifted into the form of a hideous wererat.  [Action: Shift into hybrid form]

The other guard, encouraged by his comrade, steps forward over the corpse of the fallen one and strikes out at Grugga.  Despite Rohuzar cutting down one of their own, Grugga's intimidating performance has them convinced he is the greater threat.

Shortsword - Attack: 22 Damage: 7

Shortsword - Attack: 6 Damage: 5

Back at the door, the guard curses at the loss of his sword.  Rather than pick it up, he turns to address a bigger problem.  He grabs one of the barrels from their makeshift barricade, picks it up and jams into the hole Rohuzar cut in the top of the door.  At least momentarily, Aubrey and Cosette are blocked from the rest of the fight.  The guard leans a shoulder into it to hold it in place then shouts to the other near him, "Kill that one with the whips!"

Doing his best to oblige, that guard advances on Raqisat and tries to gut him with his shortsword [with advantage thanks to the reckless attacks of Raqisat].

Shortsword - Attack: 23 Damage: 5

Shortsword - Attack: 15 Damage: 4

Finally, at the far end of the hall, a single figure stumbles out from cold darkness, another half-man half-rat creature, this one covered in rime and acid burns.  It looks at Raqisat and squeals.  From inside the darkness, you hear more screams.

Hunger of Hadar pt 2: 5 

Round 3:

1. All of you!
2. All of them!

Leelan:

Seeing the transformation you instantly recognize you are dealing with wererats, a creature you have read quite a bit about.

     Raqisat mumbles obscenities when struck but takes only 8 damage due to his rage.  Seeing one of these bastards try to seal off Cosette (and Aubrey too, technically) Raq screams out “Noooooo!” And drops his swords and attempts to grapple them. (STR check w/adv:  12 -I suck at the rolling…)

     If successful (doubtful) Raqisat uses his full movement to drag them towards the big black gloom of doom 15 feet…  if unsuccessful maybe he at least stops him from holding the barrel in place?

Grapple (contested with acrobatics):  10 

Raqisat successfully grabs the barricading guard and begins perp-walking him down the hall toward the howling blackness.

As they move away, the other guard gets a reaction attack on Raqisat with the shortsword.

Shortsword - Attack: 17 Damage: 5

The barrel is still stuck in the hole, but can be moved with a free object interaction by Aubrey or Cosette, similar to opening a door.

Round 2
(I may have be unintentionally skipped?)

Cosette clears her throat. “Dun get ahead of yerelf, ya might still fall head over heels fer us!” 

Reaction?

Seeing the disarmed guard decide to forgo his weapon and pick up a barrel to block them, in one swift motion she unsheathes her silvered rapier, “Mind if I cut in?” And jabs it through the opening with the intent on piercing him through the ribcage.

Silvered Attack: 22 Damage: 6 

Round 3

Blocked by barrel, the bard bangs the butt of her blade behind barricade. Slam. Thump. Slam. Slam. Thump. Thump. Slam. Thump. Slam. Slam. Thump. Thump. “Now let this be the drums of war. Now let this be the haunting heartbeats beneath the floor board. Now let this be the pulse to haunted memories. Now let this be the sound of our peoples song” Discordant chant follows the familiar beat. Slam. Thump. Slam. Slam. Thump. Thump. Slam. Thump. Slam. Slam. Thump. Thump.

Casting Dissonant Whispers lvl 1: 7 vs Wis DC15 

Friendly reminder: Grugga should still have Bardic Inspiration  (1d8)

Seeing the disturbing transformation, Leelan yells out.

"By the emperor’s sideburns, they’re a clan of wererats! Keep assailing them with magic! Mundane weaponry is of no avail! And whatever you do, don’t let them bite you!"

With that he turns eastward, and points his bow at the sewerfolk currently not engaged with Raqisat. Instead of pulling an arrow out of his quiver, one made of pure ice seemingly materializes in his hand. Nevertheless, it goes flying at his foe all the same.

Casting Ray of Frost:
Spell Attack: 12 Damage: 9

(If it hits, target’s speed is reduced by 10 feet until the start of my next turn)

[Cosette, I went back and checked just to make sure.  Post 3114 was your R1 turn (Vicious Mockery), then 3124 was your R2 turn (Shatter).

So the silvered attack on the barricading guard doesn't happen.

Also, the Cutting Words requires a target "you can see within 60 ft...".  At the time he completed his ability check to figure out which way to go to get out of the Blackness, he was still inside and not visible.  So I am going to rule you can't interrupt that action.  But you CAN use it to negate one of the successful attacks on Raqisat.

Dissonant Whispers goes off as described.]

Save against Dissonant Whispers:  1

The remaining guard by the door grasps his ears and looks distressed, but he seems to have shaken off the worst of Cosette's spell.  No sooner, however, is he struck by an icy blue arrow that shatters on impact, bathing his back in blistering frost.  He is still standing but looks hurt and shaken.

Rohuzar makes a quick series of chops at the transformed wererat

Attack: 11 Damage: 10 

Attack: 10 Damage: 14