Shipwrecked in Saltmarsh

It's the wee hours of the morning when all hell breaks loose.

Katernin and Kelnan wake to noise - their cabin doors opening. In the doorways stand hideous fish-faced humanoids. Dwarven shouts and cries are heard in the hold. The snapping monsters hold spears. They lunge at everything and anything.

Dain, Molo, and Fianna are less lucky. It isn't until a volley of spears begin that they awaken. They are surprised. (Fi'Finella, in the rigging abovedecks, is surprised as well.)

There's a bloodbath going on nearby in the main hold:

Sahuagin #6: Bite Attack vs Dwarf #9: 20  Piercing damage: 3
Sahuagin #6: Spear Attack vs Dwarf #9: 9  Piercing damage: 2

Sahuagin #4: Bite Attack vs Dwarf #5: 15  Piercing damage: 3
Sahuagin #4: Spear Attack vs Dwarf #5: 20  Piercing damage: 2

Sahuagin #5: Bite Attack vs Dwarf #10: 18  Piercing damage: 3
Sahuagin #5: Spear Attack vs Dwarf #10: 15  Piercing damage: 9

Sahuagin #7: Bite Attack vs Dwarf #8: 23  Piercing damage: 2
Sahuagin #7: Spear Attack vs Dwarf #8: 10  Piercing damage: 4

One of the dwarven sailors is killed outright, and three are wounded.

Roll initiative, everyone!  Everyone seasick rolls at -2 penalty.
(Also: unless you can convince me you sleep in your light armor, you are armorless. Adjust your AC accordingly! Shield okay.)

 Initiative:
Fish-faced humanoids:  2
Waking Dwarven sailors: 2
...

Fianna Initiative : 7

     Fianna wouldn't be sleeping in armor.  She doesn't think Katernan is going to kill her in her sleep... yet.

Initiative at -2. 1

Molo initiative 14 

Kelnan

Initiative (seasick): 16

(I'll roll for Katernin:) Initiative: 2

Initiative order:
Dain  - 20           (Surprised round 1)
Monsters  - 20
Kelnan  - 16
Molo  - 14          (Surprised round 1)
FIanna  - 7          (Surprised round 1)
Katernin  - 2
Dwarven Crew  - 2          (Surprised round 1)

The fish-faced creatures spring their attack:
Sahuagin #1 Bite Attack vs. Kelnan:  4  Piercing damage: 3
Sahuagin #1 Spear Attack vs. Kelnan: 17  Piercing damage: 2

Sahuagin #3 Bite Attack vs. Fianna:  9  Piercing damage: 2
Sahuagin #3 Spear Attack vs. Fianna: 5  Piercing damage: 5

Sahuagin #2 Bite Attack vs. Molo:  4  Piercing damage: 5
Sahuagin #2 Spear Attack vs. Molo: 8  Piercing damage: 3

All three are injured, which seems to excite the creatures into a frenzy.
Kelnan and Katernin may act. (Everyone else is scrambling for their weapons and gear.)

Kelnan leaps up from his meditation and throws out a Shield in the path of the creature's attacks. Golden sparks fly as the field deflects and absorbs the assaults.

(Arcane Ward: 10 HP remaining)

He grabs his rod from it's spot beside the bed and points it at the sahuagin. "Mandheg!" he shouts, casting Hold Person. (DC 14 Wis save or paralyzed)

Kelnan blocks his attacker with an arcane barrier, then counters with a new spell.
He indeed recognizes these foul fishy attackers from stories he heard while aboard the slaver: Sahuagin - "sea devils" - dreaded scourge of the coast. Evil, shark-loving maurauders known to savage coastal communities and ships alike.
Sahuagin wisdom save: 5

 The fishy fiend freezes in place in Kelnan's doorway. It emits a thin whine as it struggles to free itself from its seized-up muscles, seawater still dripping from its thick-skinned, foul-smelling body, now blocking Kelnan's door.

Katernin is up!

Katernin is up, hand on her handaxe as she gets up out of bed. She swings at the creature, calling out for protection for Fianna.

Action: Handaxe Attack
Attack: 5 Damage: 5

Bonus Action: Cast Shield of Faith on Fianna

Katernin manages to bash her attacker - a particularly large specimen of these fishy brutes - in the arm, with her axe. It bleeds a milky yellow blood and howls.

Dain, now wide awake, is up next. In his doorway stands Molo's attacker, now in a blood frenzy, prepares to savage the poor kobold with heightened ferocity.

Dain goes mad. He grabs his maul, which is never far from his side, and rushes in to fill the breach where Molo was standing. 

He’s going to Rage.  Then swing with everything he has, attacking Recklessly (-5 to hit, +10 damage) with Divine Fury adding 1d6+2 radiant damage on hit. 

Attack is at +0 to hit (adv).

Damage is 3d6+17 in a hit. 

Attack: 16 Damage: 25

With a single, raging blow, Dain destroys the sahuagin who was readying to pounce again upon Molo, smashing the creature's head clean off.

But he creatures continue their assault, unabated. Those that have drawn blood - including the one attacking Fianna - are in a savage frenzy.
Fi'Finella warns Fianna that three more are on their way downstairs from the upper deck, including an unusual-looking one. They already killed several sailors on the main deck.

Sahuagin #3: Bite Attack vs. Fianna: 14  Piercing damage: 3
Sahuagin #3: Spear Attack vs. Fianna:13  Piercing damage: 6

Sahuagin #7: Bite Attack vs. Sailor #8: 22  Piercing damage: 4
Sahuagin #7: Spear Attack vs. Sailor #8:22 Piercing damage: 8

Sahuagin #4: Bite Attack vs. Sailor #5: 18  Piercing damage: 2
Sahuagin #4: Spear Attack vs. Sailor #5:7 Piercing damage: 9

Sahuagin #6: Bite Attack vs. Sailor #9: 21  Piercing damage: 2
Sahuagin #6: Spear Attack vs. Sailor #9:20 Piercing damage: 7

Sahuagin #5: Bite Attack vs. Sailor #3: 7  Piercing damage: 2
Sahuagin #5: Spear Attack vs. Sailor #3:9 Piercing damage: 3

Two more (#8 and #9) appear at the bottom of the stairs.
#1 is still paralyzed, frozen in Kelnan's doorway.

Crit damage on Fianna: 8 - it's a nasty wound to her neck.
Another sailor is dead.

Kelnan, Molo, Fianna, and Katernin may act. (I'll resolve them either chronologically in post order or in initiative order, as I determine best. Let me know if you are doing something that requires initiative order.)

     Fianna, scrambling against the wall to (unsuccessfully) get away from this thing, finds just enough concentration to manage to cast Cure Wounds on herself (2nd level for 11 ), bathing herself in a soft green glow that comforts, soothes and heals.  

     "Kill these things!" she shouts out in a near panic.  "There's more on their way!"

Molo steps out of the room past Dain, swipes some of the blood from his wound and flicks it at the Sahuagin (1,3,7) “You’ve jumped the wrong ship!” as he casts Bane 

He then pats Dain on the arm. “Let’s get some heads, I’m right behind you.” (Take a point of combat inspiration).

The three creatures struggle for a moment with Molo's arcane curse - DC14 CHA Saves: 0, 17, 12. 

Both Fianna's and Kelnan's attackers (#1 and #7) are affected. (#1 already paralyzed as well.) Fianna's attacker manages to shrug off its effects.

Fianna manages to heal the nasty gash on her neck. Dain is inspired by Molo (Combat Inspiration) and has moved into the main cabin (between the paralyzed one and Fianna's attacker.)

Kelnan and Katernin are up next!

Dain looks across the hold.  "Those two are mine!" he screams pointing to the nearest two sahuagin.

Kelnan

"No argument from me there!" He squeezes around the creature, pushing it out of the way if necessary, and retreats back toward Dain's cabin. He fires a Ray of Frost at #4 as he passes.

Attack: 13 Damage: 2

Kelnan strikes one of the beasts assaulting a dwarven guard with a bluish ray, doing minor damage, coating one leg with frost, and getting its attention. He then moves to Molo's position.

Katernin is up!

Katernin swings her axe at the creature again, this time summoning a spectral vine that swings and lashes out at it as well.

Action: Handaxe Attack
Attack: 21 Damage: 3

Bonus Action: Cast Spiritual Weapon to attack
Attack: 17 Damage: 10