When it's Darvin's turn:

After a nod to the others, Skiaceq unfurls his wings and dives into the center of the camp. He lands silently in the tightest cluster of bewildered cultists. His scimitar cleaves upward through a cultist's back and leaves his hands, flying into the air with its ribbon on one end and tracing blood from the other. In the moment the hilt leaves them, Skiaceq's talons become a blender, madly lunging and shredding through foe after foe.

Scimitar: 14 Damage: 8
Flurry of Blows: 13 Damage: 7; Attack: 9 Damage: 7

As red flies through the air, Skiaceq snatches his falling scimitar and lunges again. To a focused eye, his targets are not random; he is removing the softest first.

Skiaceq rushes forward, flying into the melee and targeting the strongest looking cultists. The scimitar cuts open his back, and he stands for a moment but quickly falls as two talon blows to the same talon finish him off, the second hit actually protruding through to the front and coating Skiaceq in blood and tissue. 

Valji breathes fire towards the cultists, hitting two of the kobolds and one of the lesser cultists

 One of the kobolds is immediately consumed by the flames, falling to the ground scorched while a cultist and another kobold manage to barely jump clear of the worst of it. It doesn't help the cultist, however, as a bolt pierces his heart as he's turning around to look where it came from.

There is much confusion as the kobolds and cultists take notice of their attackers.

Round 2

Skiaceq
Darvin
Valji
Kobolds
Cultists

2 Cultists and 7 kobold remain, 1 of the kobolds looking extra crispy.

"You guys like dragons so much? What about now?!!?" Valji again spews forth fire, targeting as many enemies as he can! "Not so pleasant on the receiving end, is it?!!?"

(DC13 DEX save vs 6 fire damage: take half on a successful save. This spell lasts 1 minute, or 10 rounds, so there are 8 rounds remaining.)

In his periphery, Skiaceq witnesses the jet of flame that sweeps over the screaming, terrified cultists. He swallows a grim smile as his assault continues.

Whirling around, Skiaceq flips the blade above his head again and lashes talons at two foes—the survivor of Valji's first jet, and the worst-looking survivor of the second. With a graceful backstep, he catches the scimitar and falls into a defensive stance, the flat of the blade held level with his head.

Unarmed Strike: 20 Damage: 7; Bonus Attack: 13 Damage: 5

Agile Parry

Darvin pulls a lever on the side of his crossbow with his thumb like the bowyer had showed up, and sure enough, the elaborate gnomish mechanism loads another of the specially fitted bolts. "Truly a modern marvel," he thinks to himself, as he pulls the trigger to fire the bolt at the closest uninjured kobold, then looks for a spot with a boulder between himself and as many of the campers as possible.

Attack: 7 Damage: 10

As the bolt sails well wide of its mark, Darvin mutters, "Mental note: practice that 'load, fire' sequence when my life isn't in danger first."

 Skiaceq agilely jumps up and punches the crispy, knocking it to the ground while Valji runs into the fray, his dragon's breath sweeping across the battlefield, and catching the final two cultists and 1 kobolds. Two of the kobolds are killed outright as the camp scatters, cultists heading towards their weapons only a couple feet away, and the kobolds skittering toward the rocks. Skiaceq catches a kobold on his way out, his talon decapitating the unfortunate lizard with a single blow.

Skiaceq may make an opportunity attack. The two cultists run directly past Skiaceq towards their weapons. One of the cultists is badly burned, and the other has no physical marks from the breath besides a decidedly red tint.

Round 3

Skiaceq
Darvin
Valji
Kobolds
Cultists

Three uninjured kobolds have scattered in all directions while the cultists head for their weapons.

With smoke still trickling out of the corners of his mouth, Valji sees a cultist run past, trying to get to the weapons stack. Valji strikes out with his quarterstaff, aiming for the small of the human's back...

Opportunity Attack: 21 Damage: 2 

Seizing the opening, Skiaceq takes an underhand slash at the passing unscathed cultist with his scimitar.

Attack: 11 Damage: 5

Skiaceq cuts down the uninjured cultist in passing as Valji hits the remaining one decisively in the back with an audible crack sound as he limps his way towards the weapons. The remaining kobolds skitter away in all directions as the cultist looks toward the group in terror, skin bubbling where the dragon fire had bit into him, weapon held shakingly as he flinches in fear at any movement the party makes.

"Drop your weapon and surrender. If you answer our questions we will let you live. If you don't, we will let the wolves and buzzards kill you. I'd hope for wolves over the buzzards, personally. The wolves rip pretty big chunks out of you, so you'll die faster. Buzzards peck and tear at the soft parts first, like your eyeballs and your...nuggets. A slow death, that is. So, up to you..." the wizard calls out to the lone cultist, flames trickling from his mouth as he speaks.

Valji should make an Intimidation[Intelligence] check with Advantage as he uses his dragons breath to scare the cultist.

Intimidation (at least - as intimidating as a little gnome can be!): 11

It's +3 since you're using your spellcasting modifier on it (Intimidation[Intelligence]). 

Skiaceq and Darvin notice as the cultist glances behind himself, as if thinking about running in terror from the little gnome. 

You two are up.

Skiaceq stares in awe at the embers streaming from Valji's jaw. The gnome's spells are unlike anything he has seen before.

He recognizes that look in the cultist's eyes: fight or flight, and the twitch in his ankle gives away his flight impulse. Skiaceq slaps the air with his wings and lands behind the cultist, jamming his calf from behind to force him to his knees.

Athletics: 5

But the man's panic gives him just enough adrenaline to jump away. Skiaceq curses.

"Do we let him go?" he says to Darvin, with feigned menace. "One cultist can't do much, but let them gather... I say we stop him doing anymore harm here and now."

OoC: If we aren't in initiative order, Skiaceq will attempt to Help Darvin on whatever action he takes. Otherwise just flavor text.

Acrobatics: 11

Darvin is up. We're still in initiative. 

"I'm not so depraved as my friend here," Darvin-as-guard says, gesturing toward the fire-breathing gnome to his left and walking to the opposite side of the cultist from where Skiaceq and Valji are, standing as close as he can to the man. "I'll just shoot you in the back if you run. Either way, it's in your best interest to stay and chat. If you cooperate, I'll see to it that he doesn't get his hands --- or his breath --- on you." he concludes, attempting a medium-cop/bad-cop play.

Persuasion: 12

The cultist looks behind him at the gore covered bird that just tried to grab him, the crazy gnome, and the bard offering him a chance at life while still pointing a loaded crossbow bolt at him. Dropping his blade, he falls to his knees,  placing his hands behind his head in a submissive pose. From around clearing, the remaining kobolds can be heard skittering away. "What is it you want from us? We were just making some pheasant," he practically cries.

You managed to persuade him not to run, but getting him to talk will require an intimidation check. Valji has advantage as long as he maintains concentration on his spell and can use his spellcasting modifier.

OoC: Yup, we're horrible people. Especially Valji.

Darvin looks at Valji and extends an upturned palm toward the cultist, waiting for the wizard to ask his questions.