Unlike Shae, Maxine was quite keen to "hurt another grung" - in particular, their pesky leader. Presence of Faekin near by limited the options but there was one thing Maxine wanted to try for some time. He likes body experiments? She had something right for him!

Ray of Sickness (CON save 15)  Attack: 12 Damage: 13

Shae would look over her shoulder to Brax "Brax, I've got a spare dagger and boomerang should anyone need it." It could be a little late for her to offer, but it was something.

Maxine slings her spell towards the sickly looking grung leader, but he manages to dodge the projectile in the last moment. Cursing, you push back against the wall to be somewhat protected from incoming arrows.

Zip and Cliff, taking Falx's lead is pushing up against the right side of the hall, into the rough-hewn side of the cave, and readies his own crossbow to cover any advances. "Captain, we can cover from here, should any of them want to poke their heads out!"

Almost immediately after Falx called out to the Captain, a loud chirr is heard throughout the chamber, amplified by the echo. The sound seems to be piercing into your minds, droning out all other thoughts, threatening to stun you. 

Using the distraction provided by one of the elites, a grung priest rushes over to Koro-arak, and covering one of the burned areas with some sort of wrap, healing Koro- arak. 
A second grung elite quickly pops out from behind one of the pillars, and lets fly on an arrow straight for the Captain. A sharp cry lets you know that the warrior has hit his mark.
A third elite rushes over to Koro-arak, ready to guard him against incoming projectiles.

The leader himself cowers down behind the alatar, and you're unsure of what he's doing. After focusing for a moment, he pops up from behind the altar with a thorny quarterstaff, before a thin, whip-like vine covered in spikes shoots out from the staff, straight for Berrus. The flexible whip smacks against the shield, but wraps around it and the thorns bite into the skin of the dwarf's forearm, before Koro-arak violently yanks the whip towards him, causing Berrus to stumble out from the pillar and into the middle of the hallway, about five feet or so from where the torch lies on the ground.

Hearing the commotion, Faekin is lifting his head, seemingly noticing that you're in the chamber!

Professor, you're up: Please give me a Wisdom saving throw, on a 12 or lower, you're stunned. Same goes for Berrus and Shae. Maxine, you're far enough back to not be affected.

Berrus wisdom save  4

(how far from the nearest Gruk?)

not that that matters lol

The Professor:

Wisdom Save (taking advantage with his inspiration or getting advantage automatically if it is a magic effect):  18

Anyone who ended their turn next to the Flaming Sphere takes 6 fire damage (DC 13 Dexterity Save for half damage.  This may include Koro-arak if he did not move during his turn and any grung that came up to help him, depending on positioning.)  

(The Professor will continue his turn if he makes the Wisdom save).

The Professor:

Able to thrust aside the mental attack, the Professor starts molding the wind, using Gust to try and deflect any incoming ranged attacks headed for his companions as well as raise the general noise level in the room to try and drown out that chirring sound.  He motions to the flaming sphere and causes it to slam into Koro-arak again, moving it in such a way that it is adjacent to the two Grung helping Koro-arak (so that if they end their turn adjacent to it, they take the fire damage, unless it is already in that position).

Flaming Sphere bonus action fire damage to Koro-arak: 11 , DC 13 Dexterity Save for Half Damage

Calling out to Gruk, the Professor yells, "Can you drown out that chant, Gruk?!"

OOC: the grung, being natural amphibians, would have done their best to help Koro-arak without getting closer to the sphere. But you get the priest and Koro-arak on your turn.

With the gust picking up, the light of the torch flickers, but the chirring sound does not subside. Still maintaining control of the flaming sphere, you hurtle it toward Koro-arak, but as he leaps towards Faekin, you realise that your sphere might well endanger him in the future.

Gruk calls back: "It is not a technique Gruk is familiar with... only the elites can master it!"

The captain, an arrow having pierced her side, is crouching against the pillar, whispering something to Brax, before slouching against the wall and nodding to Shae, who throws her a boomerang across the stone floor. Picking it up, she takes a quick look around the pillar and throws the boomerang. You see it spin through the air, curving around the pillar and surprising the chanting elite, but missing him. The boomerang clatters against the left hand wall, about ten feet away from the Captain.

Determined to stop your gradual advance, one of the red grung starts incantations and directs intense focus towards Berrus and the middle portion of the hall. You see as sharp crystals seem to sprout from the ground,  almost like glass shards, 20 feet around Berrus. The terrain looks hazardous and difficult to get across without cutting yourself.

Berrus, please give me a wisdom save, and your action.

Wisdom Save12

i think i am stunned

if not Berrus will try to get between the Grung and Shae   

Shae's wisdom save: 15

Shae pushes through the sound threatening to stun her and begins to 'see red'. She should have never hesitated against these grung. Her head will snap to the direction the chirr came from pointing towards the creature. The warlock will glare. "Burn."

Reaction: Hellish Rebuke Dex 13 save for half damage: 20

The moment she returns her gaze back to Koro-Arak, he'd pull Berrus away from her. Her heart would sink for a moment, waiting for any movement from him. Gritting her teeth, she'll pan through the attacking grung she could see before returning her leer towards the gruk leader.

"May the light purge your darkness from this land!" Gripping her tome, Shae will release a wave of familiar radiant energy.

Casting: Word of Radiance on all visible bad grung to Shae. Con 13 save or take: 3

She'll then take tentative steps closer to Faekin if she felt safe to do so.

Ok, pure magic did not work - and why Maxine even expected it to work in the first place? - but something as simple as construction could? May be? She picked up a rock from the ground:

Catapult Dex save DC 15 at Koro-arak for 13

OOC: I forgot to add a roll for the dex save for hellish rebuke, hence the die change, but since the original roll for Koro-arak's dex save failed, I disregarded the new roll to keep the end effect the same.

Berrus, shaken by the thorny whip and the chirring sound, remains motionless in the middle of the sharp-edged crystals, in some kind of daze.

Bertrand, without any ranged weapons on hand, is trying his best tostay out of the way and remain behind Zip and Falx, ready to defend them if someone tried to rush them all. Falx, his line of fire blocked by Berrus, quickly moves tothe side to be able to provide him with cover, if anyone should attack.

As one of the elites is suddenly bathed in sacred flames,the chirring quickly turns into a scream of pain. The effect on your minds clears and you are stunned no more. Trying to get closer to Faekin, Shae invokes Kam's power on two grung on the right hand side in front of her, who seem momentarily blinded by the radiant light emanating from the tome. Shae quickly uses to opportunity to edge up and go to cover behind the next pillar.

Brax, seeing that the captian is wounded, positions himself between her and the grung, and with a nod to the firing line, pushes up one pillar to be on the same height as Shae, before quickly turning left around the pillar and strike at the singed grung with his spear. Since he had been preoccupied with Shae's sacred flames, he is caught unawares, and the spear slices clean through the muscle on the grung's upper arm.

Maxine, determined to end this fight with a decapitating strike, quickly fashions a simple sling out of a strip of cloth, and, picking up a nearby rock, flings it with power and precision towards the grung chief, catching him in the temple. You're not sure if he's out cold, or just hurt, but you definitely hit him.

Zip and Cliff, unsure of what to do, are aiming their crossbows near the altar, ready to fire at anyone that pops up from there.

Dex save elite: 22 
Con saves elite and wildling: 5 and 17
Brax spear attack: 14 vs 13
Dex save Koro-arak: 13

Having been blinded by Shae's word of radiance, the hardpressed elite is leaping back towards the next pillar and lets an arrow fly straight at Shae. Despite trying to get to cover behind the pillar, he finds a target and the arrow slices through her exposed thigh, leaving a deep gash. 

The red priest nearby leaps out from the cover of the pillar towards the altar, dodging the hail of bolts unleashed from Falx, Zip and Cliff. The first two are dodged, but Cliff waits a moment longer, and as he is momentarily unbalanced, the bolt finds its target, piercing the priest's thigh. Still, he leaps into cover towards his chief.

Once crouched behind the altar, you think he's patching up the wounded Koro-arak. The wounded elite instead slams int Brax, pushing him against the pillar and using his poisonous skin and his dagger to maximum effect. The third elite is using Berrus' apparent haze, and from the cover of his position behind one of the rear pillars lets fly another poisoned arrow, aimed directly for Berrus' chest. Mustering all his focus, Berrus manages to block the projectile with his shield though.

To your dismay, a bandage- covered Koro-arak bounds out from behind the altar and near Faekin to make the Professor's flaming sphere a more risky manouver, before lashing out with his thorn whip again. Seeing Berrus struggle and having had to expose his legs, he lashes out towards them. As it latches around Berrus' leg this time, he yanks him towards the altar, across the sharp crystals on the floor, which cut deep into his legs.

Professor, you're up! 

OOC:  Remember, enemy missile weapons should have disadvantage due to the Professor's action with the Gust spell.  Also, Zip and Cliff readied actions should go off as soon as Koro-arak jumps out from behind the altar.

The Professor:

His gusts of wind pushing and pulling at the enemy missile weapons, the Professor sees the fight get even crazier.  As the combatants close to melee range, Snively switches tactics, but still flings his flaming sphere at the back of Koro-arak, taking care to keep it away from Faekin.  But first, he uses his magic to seize a sturdy looking flask from on the altar and hurl it at Koro-arak's back!

Flaming Sphere damage for those ending their turn adjacent:  Fire = 5 damage, DC 13 Dexterity for Half

Catapult on the flask from the altar at Koro-arak's back--Let's hope it is flammable!:  7, DC 13 Dexterity to Avoid

Flaming Sphere damage for Koro-arak:  Fire = 5 damage, DC 13 Dexterity for Half

Berrus unstunned and seeing the arrow hit Shae lets out a scream of rage and will attack the closest enemy

Attack: 12 Damage: 3

Maxine decided to test if Koro-Arak is also bolt-proof:

Attack: 18 Damage: 9

Professor, as you fling the flask towards Koro-arak, it shatters against his face, and you hear his screams, as he is covered in what looks and smells like lye, burning into his flesh. On top of that, the flaming sphere careens into the chief, and although he's able to avoid the centre of the heat, the flame still touches his exposed hands, and instead of landing in cover, he slumps to the ground, unconscious.

Seeing the bloody mess that Berrus' legs had turned into, Thasselandra tries to pick out the caster responsible for the sharp crystals. Unsheathing her last dagger, she takes careful aim, before throwing the dagger at the grung priest. Though she manages to land a hit, the priests' concentration isn't broken, as he turns behind the nearest pillar, still deeply focussed on his spell.

Berrus, angry and wanting to hurt something, barrels ahead, and although his feet and legs are further cut up, he charges ahead to get to the priest responsible for his mysery. In his blind rage, he only manages a glancing blow against the priest however.

 Seeing the poor shape of Berrus, Bertrand decides to close up with him to try and bring the fight to the enemy. Using Berrus' flailing axe as a decent distraction, Bertrand waits for a good opening, and plunges his own handaxe into the unprotected thigh of the priest. With very quick reflexes however, the grung leaps out of the way, with Bertrand's axe crashing into the stone pillar with little effect.

Falx, seeing the first line bleeding and wounded badly, urges everyone else forward as he's providing cover fire with his crossbow, together with Zip. 

Shae, you're up!

For your allies:

The Professor:

OOC:  Did the Professor’s Gust spell against the enemy ranged attacks in the previous round have any effect?  In the past you have had it impose disadvantage.

Forgotten Bonus action from prior turn

Second Wind:  10

Shae would gasp in surprise, then groan in pain as an arrow slices through her thigh. It's just a scratch.

Refocusing on the battle taking place, a series of emotions would flow across Shae's face as she assesses the state of their party. It became evident very quickly that Captain Pincushion could use another patch up, but it was Berrus who she wanted to chastise for his reckless charge through the crystals. Though, she'd notice his pause for clarity, taking a breath to recentre himself for a second wind. Kam, let us share a healing breath... Shae will close her eyes to concentrate on the shared power within her, sending a familiar wave of magic to their protector.

Bonus action: Healing light (Use 1/4 D6) on Berrus: 4

As much as she wanted to run to Faekin's side, they had not secured the cave enough for her to chance risking either of their safety by bringing attention of the grung that way. Shae desired to support the Captain's effort in ending those spikes. I need eyes on that priest... Shae will search to see if she can get a line of sight to the concentrating priest, maybe he might be on her side of his post... Shae will grip her tome close. Feeding off the same desire to exterminate dark corruption, the warlock will channel another wave of divine energy to wash over all foes.

Action: If required, she will move (safely, avoiding crystals if possible) to maximize her line of sight of the grung, prioritizing the concentrating priest to send a second wave of Word of Radiance Con save: 13 Damage: 1 And if there’s enough movement, she’d return to cover.