Vax wants to end this battle before it becomes too much of an ordeal, so he flicks his wrist and sends three bolts of arcane energy flying at the creature.

Magic Missile:12

Seeing that the creature is beyond the immediate range of his hammer, Mordecai holds out his palm, fingers oddly flattened and mutters something guttural . Bright green lights extend from his fingertips as he casts ray of sickness at the creature. As he casts, he will stride forward, his stumpy legs bringing him fifteen feet from the creature's gaping maw.

Attack: 8

 On hit, damage: 7 with a constitution save of DC: 13. On e's a fail, the creature is poisoned until my next turn.

Being near the back of the group Warx attempts to move into position where he can see the creature enough to attack it with a spell.

Ice Knife Attack: 20 Damage: 3

The exploding shards do 5 cold damage to all creature within 5 feet of the target that fail a DEX saving throw.

OOC: If Warx is unable to get into position to make the attack, he will use his turn to move closer to the battle.

Vax unleashes a spray of energy bolts, which hurl into the chaos creature. The carapace seems to keep sturdy, but the strikes are true. (Chaos Creature: 9 damage)

Warx moves to the bend and hurls his Ice Knife at the monster. It strikes it in the face, causing it to shriek as a blast of cold covers the area (only catching the chaos creature)
Chaos Creature's Dexterity Saving Throw (DC 13): 18

(Typing)

Bankharn creates a shimmering barrier behind the creature, preventing its chance to burrowing away from the party. (I believe that is the way you want to place it, please confirm)

Mordercai steps forward as a sickly green ray fires towards the creature. However, its sturdy body weathers the spell, seemingly unaffected.

Yolov, Corseris, and Valentine, you're up!

Initiative (Round 2)

21: Yolov (12/12 HP, Mage Armor active)
18: Coseris (7/14 HP, concentrating on Heroism)
18: Valentine (10/10 HP)

14: Chaos Creature (uninjured)

7: Vax (10/14 HP)
4: Warx (12/16 HP)
2: Bankhan (9/16 HP, 5 THP, under Heroism)
0: Mordecai (14/18 HP)

Quote from pokepaladdy >>

 

Bankharn creates a shimmering barrier behind the creature, preventing its chance to burrowing away from the party. (I believe that is the way you want to place it, please confirm)

 (Confirmed)

"Hmm. Miscalculation on my part. Unfortunate. Good work however, Bankharn." Yolov pats Bankharn's arm. A few spins of his staff and a muttered incantation later, Yolov holds it as if meaning to using its now enchanted surface as to ward off blows(Dodge). "Keep it's attention. And if it gets to bad, we retreat. We don't want it to get too adaptive now."  

Valentine takes a good grip on her whip, steps as close she can without being to close and slash towards it with her whip. 

Damage: 4

Valentine, you need to roll attack rolls with your weapons, not just damage.

Yolov prepares for a blow, taking defensive precautions (did he move at all?)

Coseris slides up along the wall only about 10ft or so on the right side just to get 'line of sight' on the creature before holding his hand out gesturing and speaking, casting fire bolt

Attack: 11 Damage: 7

(@Poke Nope. Still where he is 30 to 35ft away from the creature last I checked). 

(Rolling attack roll for Valentine: 12)

Valentine's whip cracks, but the shell of the lobster-like monster isn't harmed.

Coseris sends fire the creatures way, but once again the hardened body resists the heat.

The Chaos Creature lets out an unearthly screech before its mouth opens up again, a spray of acid splashes forward at Valentine. The ground around her begins to disintegrate from the potent bile.
Acid Spray vs. Valentine: DC 12 Dexterity saving throw, taking 4 acid damage on a failure.

Vax, Warx, Bankhan, Mordecai, you're up!

Initiative (Round 2)

Vax tosses another trio of magic missiles at the creature.

Magic Missile damage: 14

Warx notices the distinct lack of damage to the creature after several attacks aganst it and decides to attempt to tilt the odds in the favor of the group. He casts [Tooltip Not Found] at the creature, throwing both balls of light at it.

Ball 1 Attack: 6 Damage: 6 psychic damage.

Ball 2 Attack: 9 Damage: 5 psychic damage.

If either ball is a Hit, all future attacks have Advantage until the creature succeeds on a Wisdom saving Throw. 

 OOC: just remember Bankhan gains an extra 5hp at the start of each of his turns. Until I lose concentration on the spell. 

Quote from TonyBuckets >>

 OOC: just remember Bankhan gains an extra 5hp at the start of each of his turns. Until I lose concentration on the spell. 

 (Temporary hp, though, right?)

Bankahn nods at Yolov and stumps forward.

"Let's see...how it...adapts to this,"  he exclaims, stabbing downward at the creature. His knife vibrates with energy right before he strikes.

Attack: 12 Damage: 6 and 4 thunder on movement

Yes any gains in HP from my spell is all temporary. it does not heal you or restore any of your "Natural" hit points, just added on top, so when the spell ends you will be back where you were when it started, granted you don't take more damage than the temp would give you. 

Ignoring most of the rampant spellcasting behind him, Mal let's out a bark-like shout and tries for a mighty overhand swing with his maul.

attack: 7, damage: 8

(To confirm, Heroism doesn't heal you hit points, it gives you 5 temporary hit points at the start of each of your turn. Temporary hit points do not stack and does not count towards your actual hit points.)

Vax unleashes a barrage of missiles which strike into the carapace of this lobster-like creature. (Chaos Creature: 7 damage.)

Warx Creates two motes of energy with his Distracting Din spell. However, they appear to fall upon deaf ears as the lobster creature is unimpeded.

Bankahn brings his blade of echoing energy down with a booming blade spell. However, it once again seems unaffected by the blade as the thick armour protects it.

Mordecai retrieves his maul and begins to swing. However, due to the narrow passage he and Bankahn are fighting for space so finds it too narrow a space to fight within.

(NOTE: If multiple of you are going into melee combat, you are effectively squeezing. Currently Bankahn and Mordecai are squeezing directly in front of the chaos creature, with Valentine 5 feet behind them.)

Yolov, Coseris, Valentine, you're up!

Initiative (Round 3)

Valentine tries again and strikes with her whip on the monster '' second times a charm! COME ON! '' 

attack roll: 19
damage: 2

"Acidic, but not incendiary? Curious." Yolov will lower his defensive form, and start squinting to creature, trying to discern what other chaotic qualities it possess. Or even dare it be said: "Motivation". If possible after, he makes ready to throw an Oil (flask) at it next if he sees another about ready to cast a fire based evocation. "What else do you have for else, curious thing? Acidic breathe? Explosive Form? Perhaps even a defensive form of stasis? Oh, if only this was the lab back home." Yolov continues to idly comment on. 

Arcana: 18.