Cosette gives Raq a wink then slinks ahead with her flute. She'd give Grugga's arm a squeeze to let him know she was going to try his luring tactic and for him to be prepared as back up. "Gunna try an' lure it down the hall. Rohuzar meet it at the choke point at the entrance of the hallway so range, Leelan an' Aubrey, can spread out an' pick it off from this larger room. I trust ya can take it's attention from there mah good sir." The south western room clear of water. "Raq, Grugga, I want yas teh watch mah back via a flankin' position." The room east of the large south eastern chamber. It's connected to the south eastern chamber and the hallway via doors. Positioned there they can be prepared to strike from the side/rear (southern hallway door) once it met up with Rohu. Finally, she could slip into the room to the north room to not crowd the one to the south, so the monster had a clear path to Rohuzar. She could then pop back out to flank from the other side (north hallway door). Yes it was a risk that she could get cornered, but she also knew she had others around to gamble for the potential extra advantage.

Cos touches Aubrey's shoulder to accept his offer of additional concealment, then moves into the open entrance of the hallway. Inspired by Raq's quip, she takes up the monsters banging as percussion and begins taping her foot for tempo. Inhaling a deep breath, she brings her flute to her lips and begins to play. She grows louder and louder for the sound to carry down the hallway, building in sharpness and pitch to a crescendo.

With the plan set into motion by Cosette, Leelan will take out his bow, as the battle will soon begin. He also takes out a pinch of powdered silver and iron, mutter a few words while drawing some strange arcane symbols with his hand. Once the spell is ready, the gnome will give Rohuzar a magical ward in the form of protection from evil and good.

 ‘’This should help protect you for the next 10 minutes or so.’’, he whispers before heading out to his assigned position in the large chamber south of their current position.

Grugga nods to Cosette, affirming that he has her back. He takes up the flanking position described, releases Zap near him, orders Zip to a faraway corner of the room, and draws his sword.

     "Happy to watch your back," Raqisat assures Cosette.  "But you don't need to be in front to play your song..."

As Cosette touches his shoulder, Aubrey nods and uses the powers of his talisman to turn them both invisible. He then moves into position just around the corner of the western end of the long tunnel. The young noble would let Furvus keep track of their target's movements, keeping him updated.

     "If everyone is ready?" Raqisat asks, waiting for everyone to be positioned before winking towards Cosette.  Or where he believes her to be.

I need the following checks...

Raqisat:  Stealth

Cosette:  Stealth (w/adv)

Grugga pushes himself up against the north wall of the room he and Raqisat are waiting in, to make sure he can't be seen by the creature as it passes through the hallway. He waits quietly, with teeth clenched, wondering if this will work. He nervously looks back over his shoulder a few times to check on Raqisat, but of course, everything is fine in their room... for now.

The music starts playing and Grugga wipes some sweat off his forehead. Somehow the greyscale darkvision just makes the situation seem more ominous. He hefts his sword into a fighting stances and waits.

Raqisat Stelth (in game log):  12+8 for 20

Cosette Stealth w/ Adv: 22

With the team in position, Cosette begins playing her music.  Nervous sweat drips down the explorers brows as Aubrey gives a report.

[Technically, Furvus can't just update you, Aubrey.  Since Furvus is dark blind, you will need to continue to look directly through his eyes and tell Furvus what the monster is doing and how to follow.]

As soon as Cosette begins to play, the creature turns away from the heavy metal door and and starts to move in your direction.  Slowly, at first, then racing down the halls and through rooms.  Once it reaches Hallway A, Aubrey would return to his own senses and softly warn the others that it approaches.  

Cosette is the first to see it.  A mass of pale flesh with a huge, bloodshot eye in the center.  It hovers in the middle of the hall, 10 tentacles arms surging near the ceiling and floor as it flies down the hallway.  The movement of the arms give the illusion that it is pulling itself down the hall, those the arms barely touch the floor, ceiling or walls. 

Invisible as she is, she remains undetected.  She stops playing and steps into the room with the ladder, allowing it to pass.

Raqisat, alone among the team is unable to see clearly in the dark (even Zip and Zap, Grugga's constructs, have darkvision).  He feels more than sees a large shape roar past the doorway of the room where he is hiding.

In its hunger, the creature blunders right into your trap.  As it rounds the corner in front of the ready and waiting Rohuzar, you spring into action.

[The party has a surprise round.]

Round One (Surprise)

1. Raqisat
2. Aubrey (invisible)
3. DK
4. Cosette (invisible)
5. Grugga and friends
6. Leelan
7. Rohuzar (protection)

(eep, think I misunderstood and/or assumed some things but *shurg* all good...)

     Immediately upon sensing the thing pass by him Raqisat curses his own stupidity, he shouldn't have expected it to be slow and he should have had an action readied for it passing by.  Nevermind though, things are as they are...

     Raqisat, on his turn, unhoods his lantern and lets it's light free.  Stepping into the hallway, Raqisat sets the lantern down, draws his blades and screams out a bloodthirsty howling scream and enters into a rage.  Rushing headlong at the creature, Raqisat gets right up into melee range and swings his scimitar at it.

Scimitar Attack: 11 to hit, 7 Damage

     Raqisat curses again, more colorfully this time (since I am assuming the 11 misses...), and pushes himself for all he has to take another swing. 

Action Surge Scimitar Attack:  8 to hit, 5 Damage....

     Raqisat does not know any curses colorful enough for this situation so he just sighs and ends his turn...

The tentacles parry and deflect Raqisat's strikes, preventing him from harming the floating mass at the center of the monster.

Rohuzar strikes from the opposite side, bringing his battle-axe down in a chop and cross slash, shield up and ready for the counterattack

Attack: 14 Damage: 9 

Attack: 17 Damage: 11 

On his turn, Leelan will quickly study the creature physiognomy to try and ascertain its strength and weaknesses.

Hunter’s Sense

 Using this knowledge, he will focus on those weaknesses to deal more damage.

Bonus action: Slayer’s Prey

Seeing the attack commence, Aubrey clenches his teeth and uses the power of his talisman to swiftly curse the many-tentacled aberration and then sending two golden beams of eldritch crackling force against it.

Cast Hex (dex)
Eldritch Blast: 12 Another roll if advantage due to being invisible: 9 Force: 13 Necrotic: 2
Eldritch Blast: 9 Another roll if advantage due to being invisible: 10 Force: 7 Necrotic: 2

He then moves two squares to the northeast to the door, opening it if it wasn't already open, messaging Furvus to warn him if it notices other threats approaching.

Grugga moves up to the crossroads and peeks his head into the east-west corridor to see the situation - seeing that he's blocked off from the fight, he decides to quickly slip back into the south corridor and stay quiet, hoping that the monster hasn't noticed him (hide action). He uses hand signs to order Zip up into the crossroads to fire (bonus action) then move back into the southern corridor too.

Hide: 8 (rolled in game log)
Zip attack: Attack: 15 Damage: 6

(Grugga will end up where Raqisat is on the latest map, and Zip will end up 1 square north of that. So Grugga and all his creations should be in a vertical column and hopefully all out of line of sight of the monster. If my math is right, Gruga and Zip have adequate movement for this.)

Although still invisible, Cosette hugs the doorway with the intention of using it as added cover as needed. Then as the attacks commence, she takes her turn. Like nails against a chalkboard, she grates her dagger against the wall to send uncomfortable sound and reverberation down the hall. Hopefully the effects take hold and become the bane of the creatures existence.

Casting: Bane Cha DC 15
Movement: She’d pop out and return as needed, assuming it’s safe to do so without invoking aoo