With his back facing the foe, the beast brutally bites down on Gavyn's neck and he cries out in both surprise and pain. Somehow it isn't fatal but he is in grave danger.  The tortle whirls around, swinging his battleaxe at the monstrosity.

Battleaxe Attack: 17 Damage: 8

He recalls his defense instructors words to stay focused and move minimally.  He digs deep for his reserves meant for such an occasion.

Second wind: 10

Laine mutters an arcane word under his breath. Casting Hex, Hexed Ability: Dex, Damage: Necrotic, 4

Then elects to throw another firebolt at the creature while its back is turned. Fire Bolt, To Hit: 24, Damage: Fire,  1

Deciding the barrier of celestial fire is not needed anymore as Gavyn and Kaelen has closed in to melee the wolf experiment, Nathaniel lets it fade away, then swiftly using the powers of his talisman to cast his own Hex on the abomination before unleashing a radiant beam of celestial force against it.

Bonus Action: Cast Hex (Str)
Eldritch Blast: 22 Force: 9 Necrotic: 4

Nisha's initial moment of panic gives way to her normal state of heightened alertness as the room suddenly bursts into chaos with Kaelen and Gavyn coming in from the front of the store to engage the monstrosity in a melee range, and all spells flying left and right from Laine and Nathaniel. As the creature shifts its malevolent focus towards the tortle, the sight of its destructive bite draws a deep frown of concern on the half-elf's face.

Nisha surveys the room quickly, looking for a better position that can give her an advantageous vantage point that allows her to take aim, without getting too close to the nightmarish abomination. With the size of the creature and the two huge members of their group exchanging heavy blows, and all the spell flying, it would be stupid of her to try and get in range for a close combat. 

Her golden eyes lock onto the target, calculating the timing and angle, as her fingers draw the shortbow and align an arrow. Then in one fluid motion, she pulls the bowstring tight, feeling the tension in every muscle in her body and releases the arrow.

Attack: 12 Damage: 9

Kaelen mutters a small prayer under his breath as he moves towards the creature bringing his warhammer down on it.

OOC:
Movement: Whatever is left to get to the creature

Bonus Action: cast Divine Favor

Action: Attack on creature: Attack: 18 Damage: 10 Radiant Damage from Divine Favor: 2

everyone hits except for Nisha

The Half-wolf now tasting Tortle blood attacks Gavyn again. 2x

Bite

Attack: 5 Damage: 4

Claw

Attack: 20 Damage: 3

Round 3 

The Half-wolf is moderately injured. 

Now it's the party's turn.

Kaelen brings his hammer down on the beast again and then try to move the beast away from Gavyn with his horns.

OOC:
Attack: 23 Damage: 8

Divine Favor Radiant Damage: 3

Bonus Action: Hammering Horns - Immediately after you hit a creature with a melee attack as part of the Attack action on your turn, you can use a bonus action to attempt to shove that target with your horns. The target must be no more than one size larger than you and within 5 feet of you. Unless it succeeds on a Strength saving throw (DC 12), you push it up to 10 feet away from you.

Strength Save

12

Laine continues his flame assault, throwing another bolt at the creature. 

Fire Bolt, To Hit: 24, Damage: fire, 9, Hex Damage: 1

Nisha's arrow doesn't hit its target, but the half-elf doesn't let this bother her too much. Instead, she prepares another arrow, aiming at the monster's head.

Attack: 19 Damage: 6

Impressed with his associates capacity for dealing with their enemy, the pale winged tiefling moves for a better angle as both Kaelen and Gavyn are assailing the wolven abomination, then unleashing another radiant beam of celestial force against it.

Eldritch Blast: 25 Force: 9 Necrotic: 5

Gavyn feels claws rake across his forearm, causing a grunt of pain.  He swings again the beast.

Battleaxe Attack: 22 Damage: 11

Action surge: The tortle whips is battleaxe a second time, attempting to surprise it by breaking the rhythm of his attacks.

Battleaxe Attack: 22 Damage: 5

The Half-wolf staggers back in its death throws, but then its eye cloud over milky white and it rises again. The blood spilling out of its wounds slows to a stop. The malice from this creature is replaced by some unknowable hunger. 

It attacks Gavyn 1x 

Bite

Attack: 24 Damage: 10

Round 4

Now it's the party's turn. 

Hoping to finish the wolf-hybrid experiment off, Nathaniel unleashes another radiant beam of celestial force against it.

Eldritch Blast: 13 Force: 13 Necrotic: 3

That misses. 

The second arrow hits. Nisha draws a third, but then it looks like the battle is won... only for a brief moment. As if something recharges the monster, it gets up, raging again.

"How?! How did it get up again..." she murmurs with disbelief, before drawing the third arrow. The rogue aims at the collar. 

Attack: 23   Damage 7

There is a burst of some oil liquid as Nisha arrow plunges into the collar. The Half-wolf crumples to the ground dead. 

Kaelen watches as the beast reacts to their attack and how it still has a determined vigor to take down the turtle "You must be delicious my friend, he doesn't want to let you go." he says trying to get the beast off his companion again with his horns.

OOC:
Attack: 8 Damage: 7

Divine Favor Radiant Damage: 2

Bonus Action: Hammering Horns - Immediately after you hit a creature with a melee attack as part of the Attack action on your turn, you can use a bonus action to attempt to shove that target with your horns. The target must be no more than one size larger than you and within 5 feet of you. Unless it succeeds on a Strength saving throw (DC 12), you push it up to 10 feet away from you.