Sergei will shoot another eldritch blast and keep his distance from the thing, backing as far away from it as is reasonable

Attack: 22 Damage: 8 + 1

"Confounded Gnome." Rudick mutters under his breath as he set aside Lucan once more to draw forth his hammer. "Alright you abomination. If the workshop's divine fire will not be enough for you, then have a taste of an inspired creation!" The claim is accompanied by Rudick wading forward aiming to slam the hammer into its center mass; and by extension, whatever black heart powered the thing, or so he hoped as much.

Action: Hammer of Wonder!
(One-Handed, Lethal)Warhammer - Attack: 8 Damage: 5 magical bludgeoning.

Reeling from the blow he took, Skip looks for a way to fight from further out. He grits his teeth, determined first to get another hit in himself

attack 25
damage 9
off hand attack 14
damage 8
bonus action disengage

after disengaging, Skip beats a hasty retreat, moving 25 ft away from the monster, sheathing his swords as he does, and pulling the shortbow, slung against his back, into his hands, preparing to attack from a less immediately dangerous space

Alev panics when he sees the monster's covered in flames but being completely unfazed by it. "Why is not burning?" He yells.

He loses concentration when he sees Skip leap to strike agaisnt the monster, and the bonfire extinguishes. As the others continue fighting, he cowers, wings tucked around his body and hood up over his face, as if he is trying to disappear.

As he hides there scared, a warm feeling washes over him: Something inside his heart, an ancestral memory coming from the lineage of a family he never met, an old bloodline of wind and fire. The dragon blood running through his veins awakens, and Alev casts magic around him by pure instinct.

The magic glows around him for a moment, before being casted agaisnt the monster. Alev now knows that fire doesn't harm it, which leaves only one safe choice: The glow separates into darts, just as before. This time around, each magic dart is glowing a different color, with one being red, the other blue and the last one being purple.

Alev sends the darts to strike against the creature... And just like that, the moment is gone. The warm feeling disappears, and the young aarakocra is left again just feeling cold and tired.

"I'm sorry... That's all I can do." He apologizes, his voice frail like a lost child, before he cowers again. He tries to recover the warm he just felt, but it's not coming back to him right now.

Bonus Action: Convert Sorcery Points (2)

Action: Casting Magic Missile

Red missile: 5

Blue missile: 2

Purple missile: 5

Leann curses the creature (hexblade's curse.) She then grits her teeth through the pain of the first strike it made against her, which hit and took over half of her hp away, and strikes back...
Attack: 16 Damage: 8

Sergei begins to retreat back towards the exit across the ice. As he does, he launches another arcane spear that pierces Lorghoth through its side. The vile blood that sprays from the wound splashes Rudick in the face and blinds him just before his blow would make contact. It stings as it corrodes the flesh on your face (no damage) and causes your hammer to swing wide. Wincing, Skip manages to cut off Lorgoth's leg below the knee before he escapes. Blood gushes from the wound for a moment before it solidifies into a other limb. Alev hurls three glowing bolts of energy that blast craters in its chest. As it stumbles back, Leann lashes out and delivers a deep cut into its side.

Thadalas shoots another arrow followed by a beam of radiant energy by Tomm

Arrow Attack: 22 Damage: 13

Dexterity Saving Throw: 11 and 5 radiant damage

It moans again as it attempts to smash Rudick and Leann

Against Leann~

Slam Attack: 10 Damage: 10

Against Rudick~

Slam Attack: 15 Damage: 13

Sergei will continue flash out black fire as often as he can from a safe distance

Attack: 22 Damage: 11 plus 4

"Gah! Disgusting gunk!." After wiping sludge Rudick blinks back tears to try and scan the scene. Only by the grace of the Wondermaker did he get the shield up in time to stop the block the blow to follow. Though it would nearly throw him off his feet, ass over teakettle. As he's righting himself and stepping forth again try and lay down some measure of vengeance against the creature, the lacking presence of the Paladin of Torm (or so was said), gave him pause long enough to glance around.

If able to see her in the mess, Rudick called out a word in celestial, not that he would know it, filling her with the embers of creation. Whether this comes to be or not, he turns about roaring at the mass of death, trying again to smash into it.

mmer. "Alright you abomination. If the workshop's divine fire will not be enough for you, then have a taste of an inspired creation!" The claim is accompanied by Rudick wading forward aiming to slam the hammer into its center mass; and by extension, whatever black heart powered the thing, or so he hoped as much.

Bonus Action: Cast (1st level)Healing Word on Leann, restoring 5 HP. (if Leann is unconscious.)

Action: Hammer of Wonder!
(One-Handed, Lethal)Warhammer - Attack: 17 Damage: 6 magical bludgeoning.

Leann is down.

Leann, splashing up out of the water, looks around. She pulls back from the creature, moving with the others back towards the exit.

Action" disengage. Movement: back towards the exit.

Seeing Leann go down, Skip was ready to go back to try and drag her clear. But stepping in at the right moment, again, He sees Rudick save her. 
moving further back towards the exit, Skip readies an arrow in his bow and let’s fly

attack 8

damage 8
sneak attack (if Rudick is still threatening him) 5

Desperate, and seeing the paladin lady go down before being helped by Rudick, Alev summons the skeletal hand he had learned to cast earlier to grab onto the monster. Besides that, he looks as he's ready to flee from here any second now, moving as close to the exit as he possibly can while he casts the spell. 

Casting: Chill Touch

Attack: 13 Damage: 4

Sergei makes it to the portcullis as he launches another torrent of black power that slams into Lorghoth. Rudick sends a wave of healing energy towards Leann, and she comes back to reality. She stands and bolts away from the monster across the ice towards the exit. Afterwards, Rudick smashes his hammer into its face as Lorghoth decided closes in for a bite. You knock a few grimy teeth from its malformed mouth as it feels away. You got a close look at its face when it came close. You saw that where there would normally be eyes, smooth muscle and bloody flesh lie there instead. Skip shoots an arrow, but it bounces off its corded muscles. Alev forms a spectral hand that closes in and grips Lorghoth's throat. The skin around the hand blackens and decays as mold rapidly grows on it. Tomm and Thadalas retreat back to the portcullis. Thadalas shoots an arrow while Tomm casts a healing spell on Leann. She heals for 11.

Thadalas Arrow Attack: 16 Damage: 11

Lorghoth gives a mournful groan as it lashes out at Rudick.

Slam Attack: 23 Damage: 20

Slam Attack: 16 Damage: 14

The following happens if both slam attacks hit:

It smashes you with both of its arms and latches on to you. It raises you into the air above it as you watch its head and upper half of its body splits open vertically with strands of bloody mucus stretching the gap. It lowers you into its split and closes its body around you. You are blinded, restrained, and cannot breath. At the beginning of your turn, make a DC 14 constitution saving throw or take 13 bludgeoning damage. You find yourself in a moist confinement inside of the beast. You lurch around as it stumbles towards the group. Blood and other liquids slosh around you as muscles begin to pulverized your body. You can faintly see small hands caress your body inside of the monster. You see faces press against the muscles from inside its body with with expressions of pain, sadness, and read etched in their faces. You hear a multitude of voices inside your head way in pitiful tones, "Join us... Hungry... Help me... Run!" among others. Everyone else sees Lorghoth stand straighter and grow in size as it eats Rudick .

(AC 22 Baby~ But oof! That would've been gnarly)

Rudick grimaces, but by the grace of his god, held his ground. Though the last strike came uncomfortably close to making him buckle under its strength. "C'mon you pile of walking shite! Try harder!" He taunts, slapping his hammer into his shield despite bodily protest to keep its attention on him. A step further is taken as well with him shifting through the waters to place himself between the creature and everyone else.

Movement(if necessary): Position self between Lorgoth and rest of group.

Action: Defensive Maneuver.

"Dammit, it's growing bigger..." Alev hisses, before he screams. "Rudick, are you good? That was close!"

Now convinced that this thing was just gonna grow more dangerous if allowed to keep eating, he casts Fire Bolt and hurls the mote of fire against Lorghoth's "skin" in an attempt to burn it. It might be resistant to fire, but at least it wasn't absorbing it.

Attack: 14 Damage: 10

Sergei will keep up his barrage

Attack: 18 Damage: 13 plus 2

Leann, now back by the exit, throws a javelin at the monster...

To hit: 8 Damage: 4

Skip, fear on his face as the monster attacks Rudick, seeing the thing almost eat him..........he snaps back to himself, and lets fly another arrow

attack 7
damage 8
sneak attack 4

As Rudick begins to retreat, the party fires a salvo of ranged attacks at Lorghoth, but only Leann's javelin and Alev's spell manage to impact its time rubbery hide. Thadalas shoots another arrow and Tomm calls down more divine power against it.

Thadalas Arrow Attack: 21 Damage: 6

Lorghoth dexterity saving throw: 10 or take 8 radiant damage.

You can see that while Lorghoth is a very bloody creature, there is a lot of blood splattering against the floor. Lorghoth tilts its head almost curiously before it falls to all fours and bounds across the ice. It blows last Rudick as it races towards the majority of the group. As it closes in, the upper half of its torso splits open as it bellows in rage and pain. It slams its body into Thadalas and crushes him against the wall. 

Lorghoth Trample Attack: 8 Damage: 10 

The ground shakes at the impact, and Lorghoth steps backwards as Thadalas's unconscious form slumps to the ground broken and bloody.

Reaction: AoO at Lorghoth.
(Lethal, One-handed)Warhammer - Attack: 12 Damage: 7 magical bludgeoning.

Rudick takes a swing the moment the creature tries to leave his reach. And even if that's not enough to take down the behemoth, a deep, throaty growl accompanies his march forward after the flank of the creature, before then culminating into a "Go! DOWN!" as he brought it down again hard into whatever made up the spine of the creature, for what little that mattered.

Movement: To Lorghoth flank.

Action: (Inspired)Hammer of Wonder.
(Lethal, One-handed)Warhammer - Attack: 17 Damage: 9 magical bludgeoning.

(@DM: Cashing in inspiration to give that last attack advantage.)