"Well I would be shocked if he survived that..." Samosh says after watching all the steel fly.

If the man is still standing:

Samosh smacks him with his club and a kick to the groin

smack Attack: 13 Damage: 4 

kick Attack: 12 Damage: 6

*Once per turn move the target 5 feet back on a hit.

If the man was dropped:

He moves closer to the woman and takes out some rope.

     Kaster fumbles with his crossbow, reloading it.  It is quite clear he is unaccustomed to doing it in haste and under pressure, if anyone has the time to be watching him... But he does get it done and he does fire off another shot at Yignath.  Still standing or not, the crossbow fires off towards where the man was as Kaster is hardly aiming more just firing out of panic.

Crossbow vs Yignath:  20 to hit for 5 piercing damage

Round 2

(Samosh couldn't quite make it to Yignath this turn due to difficult terrain, but the attacks also would've missed.)

Kazzira still sleeps standing up.

Yignath is still standing after the barrage of attacks, although just barely. Blood pours from his wounds, and he visibly staggers for a moment but keeps his feet. "Strike me down, it doesn't matter," he snarls. "Bane shall reward his loyal followers in the next life!" 

Yignath stumbles forward into the water toward Liatris, retrieving his spear from where it fell. He strikes out at Liatris but his wounds are too great. He misses (16 to hit).

Initiative Order
14 - Bees
13 - Samosh
12 - Kaster
12 - Liatris
10 - Kazzira
10 - Yignath
9 - Threnody

Threnody may take her Round 2 turn and everyone else can take their Round 3 turns! 

Bees, feeling extra stealthy, decides to take a moment to see where the southern passageway leads. In part, to scout ahead without the loud entourage of his group, but also to ensure they are not about to be ambushed by reinforcements. He see's the bucket headed man struggling to stand and knows his allies can finish him off. Last he'd seen of the shield holding woman she'd been asleep. Strange time for a nap if you'd asked Bees, but whatever... to each his own. Or in this case, her own.

What do we have down here?

Movement: 15 feet south.

"Then allow us to hasten your journey to your master's side." Liatris replied while cranking another hidden latch in her shield and directing the face of it towards Yignath. This time when the panel opens up in the shield, acid mists much the banite's space, threatening to melt whatever flesh it can find past the armor.

If, however, Threnody's (or Liatris) manages to put the man down, Liatris looks to Kaster and says, "Alright, hold fire. Whatever Samosh did has at least incapcitated the other one. But allow me to get some manacles on them for good measure." She requests and would go on to produce a pair of simple iron shackles from her bag of holding before wading her way closer.

Action: Cast (Cantrip)Acid Spray on Yignath. Dex Save(DC 13) or take 5 Acid Damage. 

OR(if Yig's i s downed by THrenody)

Action: Take out Manacles from Bag of Holding.

Movement: Full 30 ft(reduced to 15ft due to water) closer to the noble.

"I couldn't agree more." Threnody says impassively, pirouetting on the spot and bringing the blade of her spear as cleanly and efficiently as possible through Yignath's gut, mirroring the torture he inflicted on the sleeping noble. As blood and entrails spill from his body she slides past him. "It doesn't matter. You don't matter."

In the event that the Banite perishes, the tiefling moves towards Kazzira as she magically dozes on her feet. "Good thinking. Let's bind her before we wake her up." Threnody says, nodding towards the manacles Liatris is carrying. 

Action: Attack with One-Handed Spear on Yignath. To hit: 13, damage: 7
Bonus Action: None.
Movement: To the left of Kazzira, if Yignath dies. Otherwise she holds her ground to finish Yignath off. 

     Kaster, scared but also scared for the loss of innocent life, sees the situation mostly in hand(?) and decides to leave the fighting to those better equipped and to dash himself towards the prisoner.  He gives the Yignath person a wide berth and instead heads for the southern (by this map, assuming top is north) wall and then west towards the prison.  He likely won't quite make it (25ft move, 25ft dash) and he hesitates a bit as he approaches the sleeping woman anyway... But his main goal is to try to get to and provide care for the prisoner.

Samosh makes a shaking motion with his fist and says, "Ding dong, ya ding dong."

Casting Toll the Dead DC 13 WIS save vs 8 Necrotic Damage.

He then moves to the middle of the south pillars.

(Sorry for the delay. Work has been crazy busy for some reason!)

Yignath is able to shrug off Liatris' acid vial and dodge Threnody's spear, but the dolorous bell of Samosh's spell fills the cultist's mind. He shrieks, clutching his head, before keeling over with a splash into the water.

Meanwhile, Kazzira keeps sleeping. Combat is over! Liatris takes out a pair of manacles and binds the sleeping woman's hands. Kaster approaches the wounded man chained behind the altar. He is still sleeping too, and his body is bloody with many small wounds. 

Bees scouts a little down the southern passageway. It turns westward and continues for a while before turning southward again. There is water along the passageway until it bends to the south again. The ground there looks dry. 

Bees follows the corridor to the west, dashing through the water to make up some ground. 

Movement 30' West.

Soon as the woman is safely manacled, Liatris set to work divesting her of any weaponry next. But if doing so might risk cajooling her too much, she'd settled for at least snatching up one obvious weapon from her person and stashing it away in her [magicitem]bag of holding;bottomless satchel[/magitem] while the others carried out any other task. Though she would ask Samosh, "How long do we have before your charm ends? If its brief, then... we should prepare for some measure of resistance on her end once she comes to. But, I should caution against expecting many answers from this one. Though my experience with Banites have been mercifully few, their reputation for being rather 'determined' precedes them." 

     Kaster sees to the chained man and will seek to stabilize him before he does anything else.  He's satisfied with just cleaning and covering his wounds, using a Healers Kit to stabilize him if needed.  Once that is done he asks "Now, where do you suppose they would have kept the key," out loud but to nobody in particular and then sets about searching for such so that he can hopefully unchain this man. (Investigation to look for key: 20)

"Anything she says might be useful. Even prevarications can point to what you wish to conceal if you're not a gifted liar." Threnody says in response to Liatris' comment, before pulling one of the towels she stole from the bath-house earlier out of her pack. "Hold her firm, Liatris."

She immediately stuffs the towel into Kazzira's mouth, and expecting non-cooperation she grips the white cloth tightly around the woman's face so it has no hope of budging.

If or when Kazzira wakes, the whites of Threnody's eyes pool into a foreboding black. "Your companion is dead. You are alone. I will permit you to speak in order to answer the questions we have of you." She raises the butt end of her weapon, her voice cold and hollow, three times as loud as it normally is. "This is my spear. For every lie you tell, for every spell you attempt to cast, for every second of my time you waste, I will feed it to you in place of the towel. We will see how many teeth you have left before the end."

With that, Threnody pulls the towel away from Kazzira's mouth, ready to pounce the moment she senses even an iota of non-compliance. 

Intimidation: 15 (with advantage from Thaumaturgy )

Samoch says, "The sleep only lasts about a minute so she should be waking anytime now." nodding when the party secures her with chain and gag.