Grixx hearing the commotion will move to AL,50.  

Grixx will have his greatsword at the ready... "Tempus, see this." he says quietly to himself.

"COME MEET DEATH!" Grixx shouts.

Grixx will hold an readyattack which will be triggered by anyone except the Orc we saw earlier that was making a stand coming through the doors.

Attack: 13 Damage: 14

Bone will fire at the scholar (if the scholar dies by my companions then I will attack the bird.)

Action, both with Sharpshooter:

Attack: 15 Damage: 21

Attack: 24 Damage: 18

If I miss, Stalker's Flurry: Attack: 17 Damage: 24

Sneak Attack, if applicable: 1

Bonus Action: Hide: 26

((Jury gave Bone inspiration. Just reminding everyone. I'm not sure if it has ran out by now, but if it hasn't I'd like to use it on any save Bone has to make. Just a reminder.))

(@All: Since Dredge revealed the name of the scholar in his threat, I'll start referring to it instead. Hopefully this will make things clearer.)

Dredge is the first to react to the Nagpa's assault on Jury's intellect. Perhaps ironically, the druid offers the wizard an opportunity to recover some of his lost intelligence at the cost of becoming a savage beast, at least temporarily. The warforged mage is in no condition to resist the spell (no WIS save needed) and soon a huge wild beast takes its place in the battlefield. The Nagpa does not seem amused by either the spell or the druid's snarky remark. (Pass Without Trace is dropped.)

-> Jury is Polymorphed into a Giant Ape for the next hour, or until he loses all of his new form's HP or Dredge loses concentration on the spell.

(@Ori: I had to change a few things in interpreting your post mainly due to a speed of 40 feet not being enough for you to reach your desired ending position. Also, since you are now 15 feet tall, I had to mind your distance from the Phoenix who is currently only flying 10 feet off the ground when attempting to get you to your wanted destination. Finally, the range on the Rock attack is not long enough for you to attack without disadvantage, be it from your originally intended position or the one I am placing you in.)

Under his newly adopted name of Bailiff (cool but... how?), the once-necromancer rips some library furniture from the wall next to him, destroying many supplies in the process, carries it with him for about 40 feet (ending in the diagonal {AH58, AG59, AF60}), and throws it at the Nagpa. (I'm adding a disadvantage roll here because of the range on the attack: 24 - taking the lowest roll of 14 then). The large shelving piece misses its target by about five or six feet, destroying even more of the fragile arcane supplies in the process.

The animated doors and greatsword fly straight for the east side of the room as commanded, but do not quite reach their foe (doors and sword are at your specified positions; they broke free when you cast the spell).

(The remaining turns' resolutions are coming separately.) 

Nox transfers the Hex to the Nagpa in the form of a cheesy tramp-stamp cool arm tattoo and shoots at him three times with his arcane gift. Only one of the blasts hit the Nagpa, the other two burning some scrolls and tomes on the walls instead (Nagpa - CMD: 18). The warlock then tries to block the Nagpa's path by moving closer {AS64}.

Talon likes what he sees. He enacts a defensive Blink spell and also hurls three Eldritch Blasts at the Nagpa. Much like Nox before him, Talon hits once and destroys arcane supplies twice (Nagpa - CMD: 31). Then, he vanishes at the spot where he was last seen {AL58}.

(@Laserwhit: Please don't forget to mention in your posts how many sorcery points you used.)

Changing targets, Bone fires three arrows at the Nagpa after squeezing his eyes really hard to see better (i.e. Sharpshooter). Instead of his foe, Bone hits and breaks a magical vase, an enchanted statuette, and a jar surely containing some precious casting component liquid. Bone then hides behind the closest rune-full column (moving to {AR50} to do so).

(@Superbad: Correct me if I'm wrong but I think you added your extra Hunter's Mark damage die to your rolls against the Nagpa, even though your spell is focusing on the Phoenix. Also, that inspiration die Jury gave you has already expired since it only lasts for 10 minutes and he had inspired you even minutes before the pep-talk, which itself takes 10 minutes.)

Worried about the incoming threat, Grixx turns to the now empty doorway and prepares to attack almost anything that comes through it in the name of Tempus. And something does come. Thankfully for the new arrival, Grixx's surprise causes him to completely whiff the swing of his magical blade (ready action spent).

Entering the room appears to be a humanoid turtle. The dark green skin of the person has some brown lined patterns that match with the color of the hard shell protecting its body. Within its grasp is a sword and shield, while a chain wrapped around its body seems to hold a bunch of pieces of adventuring equipment and a stash of handaxes by the hip. The tortle in question looks around the room, attempting to survey the area and decipher the current predicament within the first few seconds. An almost imperceptible, faint golden sheen covers the tortle's body, suggesting a preemptive spell has been cast.

END OF INITIATIVE ROUND 2

INITIATIVE ROUND 3

• 22. Arclight Phoenix - flying 10 feet into the air, affected by Hunter's Mark (counter: 40 minutes);
• 22. Nagpa - affected by Hex (counter: 40 minutes);
• 19. Dredge - concentrating on Polymorph (counter: 1 hour);
• 17. Nox - concentrating on Hex (counter: 40 minutes);
• 17. Jury/Bailiff - concentrating on Animate Objects (counter: 9), affected by Feeblemind, in the form of a Giant Ape;
• 14. Talon - activated Mirror Image (counter: 9) and Blink (counter: 10);
• 14. Bone - concentrating on Hunter's Mark (counter: 40 minutes);
• 12. Grixx - activated Rage (counter: 8);
• 08. Karwin - affected by Death Ward.

UPDATED MAP:

 (Arclight Phoenix will go next)

The Arclight Phoenix will continue its elegant glide through the room. It takes advantage of its etherealness to pass through almost everyone (except for the Nagpa, Talon and Nox), and taking a peck at its original target, Grixx. While it is doing so, the electrified portal on the ceiling continues to hit the beast with lightning bolts as if it were a rod. From the flying beast, chaotic and thin lightning bolts arc towards the many arcane gadgets and supplies in the room, damaging and destroying countless artifacts.

-> Bailiff, Door#1, Door#2, Moon-Sword, Dredge, Grixx, Karwin, and Bone each take 9 lightning damage (again, no attack roll, saving throw, or opportunity attack).

-> Arclight Touch (melee weapon attack) vs Grixx: Attack: 17 Damage: 45 lightning.

Once Grixx is hit, the lightning is so strong that it searches another target to help it ground itself. It finds Dredge:

-> Dredge's DEX saving throw {DC 20} (with Danger Sense): 21 - Dredge's natural earthiness is enough for the lightning to ground without the genasi getting harmed.

-> The Phoenix finishes its flight path for the turn in the square {AS51, AR52, AQ53}, only 5 feet above ground.

-> Concentration checks all around {DC 10}:

(Nagpa will go next.)

"You and your friends unleashed my beast, Genasi, so you are now responsible for it."

"And you, stinky Tabaxi, leave me be." Casting Charm Person on Nox:

-> Nox's WIS saving throw {DC 20}: 17 but with advantage: 17 - the charmed condition seems to take hold. (OOC: Sorry about this but I used the wrong modifier on those saves. Both of these 17s are supposed to be 9s instead.)

The Nagpa then moves to {AW57} and launches its corruption at Dredge as the barbarian is on his mind after that brief conversation:

-> Dredge's CHA saving throw {DC 20}: 14 - Dredge's is considered charmed for one round.

(Everyone may post their next turn, but I keep the right to edit this post in case some of the effects above don't actually take hold depending on what you guys do.)

Bailiff howled angrily at the bird, having once more gone through him. Such anger proves fleeting as the Nagpa's words reaches his big ears. Without a second thought, it rushes over to the pillar at AK-63, rips it free, and flings it at the Nagpa; carrying not one Iota in that moment if whether Nox is harmed in the process. Immediately after, the animated objects continue their unerring rush to surround and kill the scholar.

Movement: The Bailiff ends its turn on the 3x3 square encompassed by the diagonal {AM-62, AL-63, AK-64}..)

Action: (Improvised)Rock at the Nagpa.
Attack: 12 For: 31 non-magical bludgeoning. 

Animated Objects Actions(collectively): Animated Door #1(bottom), Animated Door #2(top), and Sword(mid) end in position at AS-62, AS-63, and AT-62  respectively. As only Animated Door #1 is in range of an attack, it do so. (The others having to use the Dash action to get into their position) 

Door #2 Takes the Slam Action on the Nagpa.
Attack: 15 Damage: 18.

Lucky (feat) roll on the wis save - DC 20: 11

Nox conviced by Nagpa logic not to hit a fellow animal-human caster. Although he respond to Nagpa insult "I clean myself each day no way i smell."
He stop threathening Nagpa and sheet his rapier.

Movement : Seeing the phoenix coming closer and attacking his party members. He rush toward it with feline agility (+30 movement) AS54.
Action : He'll reach toward the phoenix with his free hand Bestow Curse WIS DC:18. if it fail the save: While cursed, the target must make a Wisdom saving throw at the start of each of its turns. If it fails, it wastes its action that turn doing nothing. hex on Nagpa drops
BA: Bardic Inspiration(+1d8 once, 10 min duration, attack/save/check) On Dredge

Karwin isn't really sure entirely what is happening. The memories of her prior life are still a hazy mist. She does, however, recall some of them being her allies at some point. However, this birdlike creature is definitely not one of them. She incants a spell to enhance her blade and strides towards the beast and slashes with her weapon.

Bonus Action: cast Magic Weapon upon her longsword (now concentrating)

Movement: move to AQ-50 (I think that's adjacent to the Arclight Phoenix)

Action: Attack the Arclight Phoenix.

Longsword vs. Arclight Phoenix: 17 vs. AC. Hit: 12 magical slashing damage.
Longsword vs. Arclight Phoenix: 26 vs. AC. Hit: 14 magical slashing damage.

Dredge mutters under his breath as his form begins to grow. “Stupid misguided creature, I pity your plight, but I can not continue this dance.” Dredge’s earthen skin grows hard, but retains it’s texture. Dredge’s height nearly doubles as he finishes his transformation, becoming a full fledged Earth Elemental. He then sinks into the ground and dashes under the earth to AQ66, joining Nox and the Nagpa outside of the flightpath of the bird while remaining under the floor.

==Talon=Dwarf=Sorcerer/Warlock==

Talon knows that this scholar creature is a powerful magic user but still makes an attempt to transform it.  If he is able to succeed in the transformation the reward is possible success in this encounter.  Talon reappears at AJ, 57 he uses his magic bloodline to cast Polymorph at Nagpa using 1 sorcery point to enable the distance (60ft * 2).

If the Nagpa fails it's saving throw (DC 17 Wisdom) he will turn into a Killer Whale.

Either way Talon will then move to A0, 57.  

Blink roll: 10    Talon does NOT disappear.

"FINALLY!", Grixx shouts as he sees the Arclight Phoenix near the ground.

The raging barbarian will charge to AS,51 under the Phoenix so that his Greatsword will reach it.

Grixx will make two reckless attacks against the Phoenix slicing at it's underbelly.

Attack 1:

Attack: 24 Damage: 15

Attack 2:

Attack: 24 Damage: 15

Divine Fury Damage (Radiant) for First Attack that Hits:  12

((Gonna roll to see who Bone attacks: 1-3 for Phoenix, 4-6 for Nagpa: 5))

Bone will quickly asses the two hostile entities and attack the Nagpa, casting Lightning Arrow.

Action:

Lightning Arrow: Attack: 24 Damage: 14 (half on DC 16 Dex Save. Creatures within 10 feet must make the same DC 16 Dex Save, if they fail they take 9 lightning damage, half on a success)

((I'm not sure if I still get my second arrow and my stalkers flurry so I will roll those in a spoiler below))

Bonus Action: Casted [spell]Lightning Arrow[spell].

Sneak Attack, if applicable: 4

EDIT:

Dredge takes his full elemental form and melds into the room's stone floor. Where he is only he knows, or so it would seem.

Convinced that there is only one threat in the room now, Nox rushes towards the huge lightning bird and touches it. This simple act is enough for the tabaxi to feel his finger muscles get stiff (i.e. Nox takes 13 lightning damage -> concentration check on Hex {DC 10}: 19). Despite being able to maintain his focus on his current spell, Nox voluntarily drops it in order to be able to cast Bestow Curse (recall than concentration drops as soon as you begin casting another concentration spell, as we determined earlier in this campaign.) 

-> Arclight Phoenix's WIS saving throw {DC 18}: 7 - the beast is cursed. Dredge feels inspired by Nox's courage in touching a being made of pure lightning (d8 Bardic Inspiration die).

-> Nox is still under the effects of Charm Person as the damage he took was not from an active harmful decision by the Phoenix, at least that's how I'm ruling it.

Meanwhile, Bailiff's animated objects continue theirs pursue of the Nagpa. They, however, seem to approach their target with some lag, surrounding the area the scholar had left just a moment earlier. (Please notice that the Nagpa had moved to {AW57} as per the post above detailing his turn -> no attack for Door#2 then...)

Bailiff himself is a bit quicker to catch up to the Nagpa's move, hurling an up-until-recently-arcane column at the scholar. The column misses by seven or so feet this time, doing further damage to the knowledge contained on the walls.

(@Superbad: You are using the attack action, so you second arrow is indeed shot. Since it missed, Stalker's Flurry triggers successfully. There is no one around the Nagpa though and you are not attacking with advantage (your previous hide action did not surpass the Nagpa's passive perception), so Sneak Attack does not trigger. Regarding the spell, note that the saving throw only applies to those within 10 feet of the target, which in this case is no one. Finally, only your first arrow benefits from the spell.)

Despite being right next to the low-flying Phoenix, Bone releases a Lightning Arrow at the Nagpa, losing his Hunter's Mark in the process. The well-themed spell for the current situation hits the scholar, but Bone does not stop at that. The kenku releases two additional arrows, one of which also damages the strange humanoid (Nagpa - CMD: 68).

Talon then adds insult to injury by trying to transform the Nagpa with Polymorph:

-> Nagpa's WIS saving throw {DC 17}: 11 - "Noooooooo....." a high-pitched scream and a fist shake accompany the transformation into a Killer Whale Calf (that Nat1 deserves a bit more humiliation, so baby whale it is...).

Talon celebrates by not escaping into the Ethereal Plane.

Grixx runs forward with anger, his head moving within the electric bird (i.e. Grixx takes 7 lightning damage). He then slices the bird twice (taking another 10 lightning damage for the first slice and yet another 11 lightning damage for the second.) The barbarian is a bit surprised that gutting pure lightning does not end the same way as gutting a bird would, but he can feel that the magic in his blade dealt damage nonetheless (Arclight Phoenix - CMD: 99).

Seeing the curious display of bravery, Karwin steps forward while focusing on Magic Weapon. She stands side-by-side with Bone and attacks the Phoenix twice, hitting once (Arclight Phoenix - CMD: 113).

At this point, Karwin's pursuers catch up to her. A familiar irritating voice shouts from within an ethereal rainbow-colored robe: "What is going on here..." The Gith Announcer (Dredge knows him to be named Furloth) leads what looks like one entire battalion of armored soldiers, if not six.

-> Furloth's initiative: 8 (I'm electing to add a -3 modifier to this roll to account for his "surprise" upon arrival.)

-> Karwin takes 8 lightning damage from hitting the Phoenix once.

(If it weren't for those guards reaching the Horn of Silent Alarm, this fight would be pretty much over by now with that Bestow Curse and that Polymorph)

END OF INITIATIVE ROUND 3

INITIATIVE ROUND 4

• 22. Arclight Phoenix (CMD: 113) - flying 5 feet into the air, affected by Bestow Curse (counter: 10);
• 22. Nagpa (CMD: 68) - affected by Polymorph (counter: 1 hour), in the shape of a Killer Whale;
• 19. Dredge - concentrating on Polymorph (counter: 1 hour), in the shape of a Earth Elemental;
• 17. Nox - concentrating on Bestow Curse (counter: 10), affected by Charm Person (counter: 1 hour);
• 17. Jury/Bailiff - concentrating on Animate Objects (counter: 8), affected by Feeblemind, in the form of a Giant Ape;
• 15. Furloth (CMD: 0) 
• 14. Talon - activated Mirror Image (counter: 8) and Blink (counter: 9), concentrating on Polymorph (counter: 1 hour);
• 14. Bone 
• 12. Grixx - activated Rage (counter: 7);
• 08. Karwin - affected by Death Ward (counter: 8 hours), concentrating on Magic Weapon (counter: 1 hour).
• Armored Guards killed: 0

UPDATED MAP:

NOTE: The armored guards are going to be mechanically part of the environment, not actual, turn-taking combatants in this fight. At the end of each of your turns, each of you should additionally roll two crossbow attacks against yourselves. These two attacks per turn have a +4 to hit and deal 1d6+2 piercing damage. Please note that you guys should be rolling these attacks yourselves, to expedite things.

NOTE: You may elect to attack the armored guards. In this case, just assume that you hit and/or they fail the saving throw. Every 10 points worth of damage that you cause, a guard dies. I'll keep a counter. There are a lot of them.

(Phoenix and Nagpa go next.)

-> Arclight Phoenix's WIS saving throw {DC 18} vs. the effects of Bestow Curse: 9.

Sorry about this fluke post...

-> Arclight Phoenix's WIS saving throw {DC 18} vs. the effects of Bestow Curse: 10.

Despite not being able to attack, the Phoenix will continue to fly around, passing through everyone one of you except Dredge.

-> Grixx, Bone, Karwin, Nox, Talon, Bailiff, Door#1, Door#2, and Animated Sword each take 12 lightning damage. This one does count against Charm Person, so Nox is no longer charmed.

-> Concentration check all around {DC 10}:

 -> The Phoenix end in the diagonal {AT59, AS59, AR60}, 30 feet into the air.

The Nagpa will simply use its Keen Hearing to perform a search to try to find out if anyone is near him... (what a mockery...): 21 - great power comes with great responsibility, and a steep learning curve, it seems...

(Dredge, Nox, and Bailiff are up next. Don't forget our new environment/guard mechanic. It also applies to the animated objects, since each of them is a creature.)