Nirzeg Wisdom Save(DC 12): 7.

"Not.. like..." The rest dies in the Githyanki's throat. For despite Nirzeg's efforts to resist, he was no Githzerai. As he stood there slack jawed, with a command to follow, a still hidden Zeek stood as well staring and batting at the patterns.

Zeek Wisdom Save(DC 12): 10.

Smart Bird Roll: 20

Swiper shields his eyes quick enough to avoid the hypnotizing effect. When the moment passes, he can see that Nirzeg and Lydia are both standing there, stupefied. 

The pretty serpents and nice smells were all a ruse! That wasn't candy at all! Enraged at this deceit, the small kenku fires a bolt at the caster!

Attack: 21 Damage: 6
Not sure if the dude sees me or not, but heres a sneaky taco if not: 7

The crossbow bolt grazes the caster’s armor. He stared daggers in Swiper’s direction.

Wisdom: 11

Advantage Rolls:

Nirzeg's Wis Save(DC 12): 8.

Zeek's Wis Save(DC 12): 13.

(@All: See Discord for rolls)

Though the master is unable to shake his descent into madness, Zeek, ever the willful cretin, realizes now's not the time to play with colorful snakes! The Tressym then flutters over to paw at Nirzeg's ear, face, and finally more modifly shove at his head to try and get the Gith's attention. Whether he succeeds or not, Zeek then flies off for cover once more.

Zeek's Action: To try and Shake Nirzeg.

Zeek is able to snap Nirzeg out of the trance. Nirzeg is now no longer charmed or incapacitated!

Derrikoth's movement gives many of the barbarians the opportunity to get in a strike as he rushes past, desperate to get to the shaman who has put a spell on his friends.

Opportunity Attack: 11 Damage: 15 slashing

Opportunity Attack: 14 Damage: 5 slashing

Opportunity Attack: 19 Damage: 11 slashing

Opportunity Attack: 18 Damage: 6 slashing

Quote from Persuasion >>

Attack: 17 Damage: 4

Attack: 21 Damage: 13

Attack: 21 Damage: 15

Attack: 18 Damage: 8

 Surging with adrenaline, the dragonborn skewers the hapless shaman on his lance. The shaman, who hadn't even seen it coming, looks with surprise at Derrikoth. He coughs up blood, then his eyes roll into the back of his head and he collapses.

// Lydia and Rasa are now free of the charming effect! //

With her mental faculties restored, Lydia will now cast Call Lightning and hurl down a bolt at the barbarians. (She's aiming towards the blue line I drew in Roll20)

Quote from Sarcasticfury >>

 

14 DC15 Dex Save for half.

 // Barb saving throws 2, 13, 14 //

// Also need a saving throw from Sparky! //

Sparky Dex: 18

ACTION: Firebolt on Barbarian Attack: 14 Damage: 14

Enhanced Bond Roll: 4 (added to damage of firebolt)

BONUS ACTION: Sparky flame seed on same Barbarian: Attack: 15 Damage: 7

Taking heavy hits from Rasa and Lydia, the scorched and bloodied barbarians all point at the two casters and yell "BAIDAS!!" 

They rush down the stairs, eyes wide with...fear? Malice?

The barbarians unleash a ululating warcry. At the same time, you hear Harshnag's booming voice behind you—"Look out!" 

A shadow passes between Lydia's stormcloud and light spell, accompanied by a rush of cold air. Out of nowhere, a white dragon, larger than Josephus, swoops low to pick up the spear-wielding barbarian leader. The leader leaps upon the back of the flying creature, and they take off into the air together, flying somewhere above Lydia's big storm cloud.  

// Players up! The barbarians are bum-rushing Lydia and Rasa, from the looks of it, and Harshnag is running to help. The white dragon is currently flying somewhere above Lydia's storm cloud, in the darkness. //  

Nirzeg knew he should've been terrified at the winged beast. Instead, he grinned and even cheered himself. "Yeeehesss! Just what I needed! Stay spread out, least you wish to die! Harshnag! See if you can bring to the earth whenever you can!" Nirzeg calls out, just before gesturing sharply at the charging barbarian's direction and sending another flask of oil flying at the thickest collection of charging barbarians.

Without even looking to see if he's successful or not, both he and Zeek retreated a ways.

Action: Activate at (1st level)Purpolser(Dex 14) on a Big Barbarian, inflicting 10 magical bludgeoning damage on a failure and be covered in oil. On a success, next target in line must make the same save.

Derrikoth stares at the white dragon, caught off guard in momentary awe. When he senses return to him, he charges, feeling rejuvenated.

Second Wind: 7

Two Attacks (One at each of the barbarians nearest him)

Left Barb: 17 Damage: 15

Right Barb: 26 Damage: 13

Nirzeg finds that an ice-covered wall impedes his retreat. It could potentially be climbed with some sort of spikes or ice axes. But his flask of oil zooms past the first barbarian to hit the one behind him squarely in the face. The barbarian (marked on the map) is covered in oil. 

Zeek, on top of the landing 20 feet above the rest of you, can see that there seem to be no threats in his immediate vicinity.

Derrikoth gives chase and connects with each of his targets, but they are single-minded, running pell-mell down the stairs. 

// Lydia, Rasa, Swiper! The barbarians are charging down the stairs towards you. What do you do? //

Lydia will send down another bolt of lightning, right where it's circled in blue on roll20.

DC14 Dex Save to take half of 16

Lydia kills one of the Barbarians with the lightning strike, and severely wounds two more.

// Rasa and Swiper! //

Swiper hides behind Lydia as a bonus action!

Stealth: 20 (I can't remember if Pass Without Trace is up, but add 10 to this if it is)

Then he shoots at one of the guys that Lydia almost killed!

Attack: 19 Damage: Unable to parse dice roll.

Sneak: 13