(Sorry for the delay! Things have been very busy recently.)

Initative Order: Shishalki, Phylo, Syvis, Thodek, Myconid, Nicholas

Thodek saves are both failures (unfortunately, it is not a poison effect, but good on you for keeping track of that— I will let you know when it’s applicable). This means Thodek is stunned for the next minute (but may attempt to save at the end of his turn), and takes 12 acid damage. 

Syvis takes aim at the sovereign, but the bolt fires wide, missing Phylo (Miss).

Thodek is stunned, so is unable to do anything, but feel free to roll another con save to attempt to save at the end of your turn (DC 12)

Myconid are up!

The final one remaining rushes towards Syvis and makes a slam attack against her:

Attack: 7 Damage: 8

The attack misses!

Nicholas and Shishalki are up! Map has been updated, sorry again for such a delay; what would you like to do?

Thodek con save: 12

Nicholas continus to keep the fire on Phylo even as the poison continues to courses through his veins.

Action: Attack: 8 Damage: 4 (2/4 bullets before reload)
Move: None
Bonus Action: None

(Wow! Crit with Disadvantage :D)

Shishakli will rotate north east and hope to take out the final minion.

Initative Order: Shishalki, Phylo, Syvis, Thodek, Myconid, Nicholas

That is a success by Thodek on the con save. You snap out of the paralysis, and are rushed back into the fight, Phylo standing right in front of you.

Nicholas fires at Phylo, again his aim rings true despite the poison slowly taking over his system (-12hp (Total: -99hp)).

Then, as a legendary action after Nicholas’ turn, Phylo destroys the final myconid in front of Syvis in order to recover 7 hp. (+7hp (Total: -92hp ))

Shishalki then shoots (since there is no longer a myconid, I will just redirect it to Phylo), aiming at the sovereign and further injuring Phylo (-8hp (Total: -100hp))

Phylo is up!

Phylo grimaces at Thodek, but nevertheless, the sovereign grits it’s teeth and attacks you with a fist:

Attack: 14 Damage: 14

(Which is a miss!)

Syvis and Thodek are up! Map has been updated; what would you like to do? 

Thodek moves up to Phylo and swings with both his hammers, physical and spiritual.

Attack: 9 Damage: 8

Attack: 10 Damage: 8

Taking a deep breath, Syvis leans a hand against the tower to steady herself and fires again.

Crossbow: Attack: 6 Damage: 15

Initiative Order: Shishalki, Phylo, Syvis, Thodek, Myconid, Nicholas

Syvis takes another shot at the sovereign, but the bolt again fires wide (Miss).

Thodek then swings his hammer, smashing into the side of Phylo, however the spiritual weapon still swings wide and misses the large myconid (-11hp (Total: -111hp)). 

Nicholas and Shishalki are up! Syvis and Thodek, feel free to queue your action as well if you would like. No changes to the map; what would you like to do?

Shishakli continues rotating around, trying to find new areas of darkness in which to hide, and continues to shoot arrows, now focusing on Phylo, as only he remains.

Attack: 17 Damage: 9

Syvis sits down heavily, too woozy from the poison to continue standing, and fires another bolt.

Crossbow - Attack: 18 Damage: 13

Nicholas continues to fight through the poison and fire at Phylo.

Action: Attack: 20 Damage: 12 (1/4 bullets before reload)
Move: None
Bonus Action: None

Initiative Order: Shishalki, Phylo, Syvis, Thodek, Myconid, Nicholas

Nicholas fires another bullet towards Phylo, but the attack flies wide and misses the sovereign. 

Then, Shishalki follows this up by loosing an arrow at the sovereign, firing true and striking Phylo who lets out a cry of pain. Now, with countless arrows riddling it’s body, Phylo gives one final mangled scream than echoes and reverberates through the chamber as the sovereign writhes and twitches before finally falling silent, limp, apparently dead. 

With this, the haze of the battle clears, your heartbeat slows, and you return to a semi-state of calm. We are now officially out of combat… what would you like to do?

 Syvis spends the next ~40 second or so fighting the urge to puke while sitting on the ground until the temporary poisoning eventually passes. She doesn't rise right away but just looks at her companions, expressionless as ever, just trying to keep her eyes focused.

She slowly manages to push herself to a kneeling position, still not confident enough to get back to her feet. "Someone should check with the others. See if all is well and safe. Are the affected myconid still under the Lady of Rot's sway?"

Thodek takes a moment to kneel down and give a prayer of thanks to Moradin before rising to look around, "I'm afraid my abilities for healing are expended, but is everyone alright?"

Shishakli silently begins to collect as many arrows as he can ((I honestly don’t remember how many he fired during this combat… 10ish? 15ish?)), he looks around the area and says, “Let us only hope the demon was not successfully summoned…”

Syvis quietly sighs and slowly climbs to her feet. After taking a moment to steady herself she begins walking back toward where they left the others.

Ivan breathes a sigh of relief as the Phlyo falls. He waits a moment to be sure the danger has passed before moving over to Phylo and searching the fallen Myconid's body, "Is everyone ok? What do we do next?"

Ok, Shishalki, let’s say that you can recover 5 arrows from that fight. 

Nicholas: Searching Phylo’s body, you don’t find much other than two spells scrolls. One for the spell magic circle and the other for plant growth. (Which you may use however you would like.)

Ok, and so after this everyone in the group would be able to regroup and meet up with each other. What is the plan from here; what would you like to do?

Thodek would continue with Syvis and head back to the others, "It seems the immediate threat has passed for the moment. Do you know a way for us to get to the surface?"

Not gifted in the arcane, Nicholas would hand the scrolls to Thodek, "Found these. May be useful, but I can't make heads or tails of them."

Hearing Thodek's question,  Nicholas' ears perk up as he too awaits the answer.