Shipwrecked in Saltmarsh

Molo and Fianna make their way up and onto the deck and to the port rail. The wind is cold, and visibility poor. A small rocky islet - little more than a jumble of boulders and dead brush - lay to port. Humanoid figures fly overhead - you glimpse wings and human faces in the swirling, stinging sleet. Much of the dwarven crew has joined them in the wonder of the spectacle, although others are unmoved, shouting and running.

Winged figures: 
Initiative: 21

The winged figures continue singing and flying.
Dain, Kelnan, and Katernin may act.

(BTW: Long rest. It's been more than 8 hours since your morning run-in with the interdimensional spider.)

Dain, Kelnan, and Katernin may act next.

They are currently belowdecks, while Fianna and Molo have quietly gone above to see who is singing. Shouts can be heard above as the ship has grounded with an alarming lurch on a small, rocky islet. Visibility is poor, the light is waning, sleet is falling, the cold wind is gusting, the swells are large and grinding the ship in a dangerous way against icy, barnacle-covered boulders.

Dain grabs his trusty maul and rushes up onto the deck as fast as he can to see what is going on.   (Using his Action to Dash, I'd assume, though note I have 35 ft. of movement now I'm 5th level)

Dain races upstairs onto the cold, gusty, and now slanting outer deck. He can make out the rocky islet to port through thick, stinging sleet. Humanoid figures fly overhead on birdlike wings, too high to see much (or swing a maul at.) Some of the dwarven crew are shouting at each other, trying to assess the damage and get the sails down before the situation gets worse. But others have joined Molo and Fianna in following the song, which Dain has no interest in given the circumstances. Molo, Fianna, and several crew members appear to be preparing to climb over the rail and down onto the icy rocks.

Kelnan and Katernin may act next.

Kelnan grumbles about how he will never set foot on a ship again because EVERY TRIP is a disaster, slaps Mage Armor upon himself, and marches up above decks shouting at the dwarves.

"Secure your crewmates, if you would! Seems to be some wily magic about."

Arcane Ward: 14/14 HP

(Apologies for the delay, everyone! A lot going on here. Will post tonight.)

Initiative (reordered):

Winged Figures: 21
Molo: 19 (Incapacitated but may reroll the DC 11 Wisdom saving throw to break the charm)
Fianna: 18 (Incapacitated but may reroll the DC 11 Wisdom saving throw to break the charm)
Dain: 18
Kelnan: 17
Katernin: 14

With a flurry of wings, two of the winged humanoids attacks Kelnan with claws and sticks:
#1 Claws Attack vs. Kelnan: 11  Hit: 6 slashing damage.
#1 Club Attack vs Kelnan: 19  Hit: 2 bludgeoning damage.
#2 Claws Attack vs. Kelnan: 11 Hit: 8 slashing damage.
#2 Club Attack vs Kelnan: roll]1d20+3[/roll] Hit: 3 bludgeoning damage.

Two more go after dwarven crewmembers:
#3 Claws Attack vs. Dwarf 1: 12  Hit: 5 slashing damage.
#3 Club Attack vs Dwarf 1:9  Hit: 2 bludgeoning damage.
#4 Claws Attack vs. Dwarf 2: 20  Hit: 5 slashing damage.
#4 Club Attack vs Dwarf 2:21  Hit: 3 bludgeoning damage.

(Sorry - reroll on that broken bracket: 4 )
(And crit damage: +8 )
The flying humanoids tear his arcane ward to shreds, and dig into his arm painfully. Both attacked dwarves are seriously wounded.

Molo and Fianna climb down onto the rocks, as do many of the crewmembers, and scramble through the thin scrub and icy boulders toward the center of the island.
They may make a DC 11 Wisdom saving throw to break their charm. (But can't act until next turn.)

But the singing becomes stronger and sweeter.
Dain, Kelnan and Katernin must make a new DC 11 Wisdom saving throw at disadvantage or be charmed. (If they succeed they may act. Four of the creatures are within melee range of Kelnan and the crew.)

Molo wisdom save 13 

Dain Wisdom Save (with Disadvantage):   3

Dain falls under the strange spell weaved by the singing, as Molo wakes from it.

Fianna, down onto the rocks, may make a DC 11 Wisdom saving throw to break her charm. (But can't act until next turn. Nor can Molo.)

Kelnan (still bleeding slightly from his wound) and Katernin must make a new DC 11 Wisdom saving throw at disadvantage or be charmed. (If they succeed they may act. Four of the creatures are within melee range of Kelnan and the crew. Katernin is not far away either.)

23 Fianna Wis save.

19 2nd save in case this is a type of Charm as I’d have advantage if so.  If not a charm, ignore..,

…

Neither seem good enough anyway so Fianba uses her Favored by the Gods feature to add 4 to the score…

…

11 or 12 if advantage do I think Fianna breaks free… 

Kelnan

(Advantage vs charm + disadvantage should mean normal roll, right?)

Wisdom save: 19

(Assuming there's a way to target it...)

Kelnan concentrates an orb of extreme heat and ignites it into a Fireball encompassing as many of the creatures as he can including those attacking him, while avoiding friendly targets.

38 fire damage, DC 15 Dex save for half

Wis Save: 8

Fianna wakes from her trance as well, while Kelnan and Katernin manage to ignore the charming tune.

Kelnan launches a massive ball of flame into the swirling mix of sleet and wings above.

Dex Saves: 4,  20,  4,  8,  5,  15,  17,  7.

Horrible shrieks erupt from the sky. Burned feathers fall through the air into the black water and flaming winged forms swoop in panicked loops. But then the moment ends, and none fall from the sky. The songs continue.

Katernin may act next.

Three of the unaffected dwarven crew fire the ballista at one of the flying humanoids.
Ballista Attack: 22   Hit: 13 piercing damage.

They skewer one. It falls shrieking into the sea.

Katernin may act next.

Harpies continue to harass Kelnan, Katernin, and the ballista operators:

#1 Claws Attack vs. Kelnan: 5 Hit: 5 slashing damage.
#1 Club Attack vs Kelnan:21 Hit: 2 bludgeoning damage.

#2 Claws Attack vs. Katernin: 18 Hit: 7 slashing damage.
#2 Club Attack vs Katernin: 17 Hit: 2 bludgeoning damage.

Three more go after dwarven ballista operators:
#3 Claws Attack vs. Dwarf 1: 12 Hit: 5 slashing damage.
#3 Club Attack vs Dwarf 1: 12 Hit: 2 bludgeoning damage.
#4 Claws Attack vs. Dwarf 2: 15 Hit: 6 slashing damage.
#4 Club Attack vs Dwarf 2: 22 Hit: 5 bludgeoning damage.
#5 Claws Attack vs. Dwarf 3: 23 Hit: 6 slashing damage.
#5 Club Attack vs Dwarf 3: 18 Hit: 2 bludgeoning damage.

Two of the dwarves fall to the harpies, who continue their sickly sweet songs. A third is wounded.

Everyone except Dain must make a new DC 11 Wisdom saving throw at disadvantage or be charmed (again!)

If you succeed, you may act next. Dain, having scrambled out of the ship into the rocks, begins to climb toward the middle of the barren islet in the swirling sleet.

Katernin raises up her hands and cries out, sucking all the sound from the surrounding area out

((Casting Silence centered on where the majority of the fighting is taking place))

Fianna Wisdom Save: 6

Though she has advantage against being charmed.  But first roll was the losing one... Mainly editing to add this to try to remember next time.

Molo wis save at disadvantage 3 

Katernin creates an arcane bubble of pure silence - the din of the ocean, the grind of the ship against the rocky shore, the shouting of the dwarves, the harsh hiss of sleet gusting against the deck, and (most importantly) the alluring songs of the harpies are completely silenced for all but Kelnan, and for Katernin herself.

One harpy remains outside the bubble as well, but she was not singing at the moment the spell was cast. The charm is, for now,  broken for all.

Everyone may act (including Dain, Fianna, and Molo. However, nobody except Kelnan and Katernin may cast a spell with a verbal component. )