The Wave Crashers Demise

Upon Pirate Jim coming on to the deck of the Wave Crasher , a loud crack erupted into the air and I found myself tossed into the water. Mozen and the rest of the crew call out as they notice that the starboard side of the ship is being attacked by Sahuagin, the same that attacked us before at the festival. Thankfully I am able to cast "unseen servant" and ferry myself back on to the boat while the others around me start the battle.
 
Once i have settled deck side, I turned to see Halebor battling two of these fish fries, trapped between them. I offer my assistance by shooting an arrow, which unfortunately falls short. I watch as Gertie, who is across the boat, cleaves of the Sahuagin in half, launching its remains into the depths.
 
The Sahuagin between Mozen and Halebor casts a horrific spell on its weapon which seems to have some type of crystal fueling it. Though I was not able to negate all damage, by quickly scrabbling away I was able to get out of immediate danger. With a final blow from Jesper, the creature lunges its sword into its own abdomen. With its final breaths it launches a fireball in our direction leading to all three us of sustaining damage, Mozen being knocked completely
 
Just as we think that the battle is behind us, a great shadow emerges from the water. A Sahuagin hatchling swarm has risen to attack us next! We fight off a few before Jesper, Mozen and I head down to the bottom of the ship to try and repair the hole. With supplies that found we where able to shore up the leak and make the ship sea worthy again!
 
As we ran back up to the upper deck, we see a green flash and hear a voice...what is going on now?!