Holding Action:
As soon as it starts ripping the net, Garu will attack using her jian. 

OOC: She would have used her Nature's Wrath but realized you have to be able to see the target (unless you rule that seeing the motion in the water suffices, then I will do that). 

Aisha will shout There sure arre a lot of fish! This one has never seen so many! her eye's staying on the disturbance, and waits until it gets closer, likely around the same time as Garu strikes, would leap at it, attempting to grapple it, even using her claws, after having taken a heaving, large breath. 

(Not sure what I'd need to roll in this situation or at what)

Upon seeing the tear in the net and the movement of the Wyso's toward it, Abraxas stares. "What is happening? Can anyone tell?" He readies Dispel Magic, looking for a target.

Harmony waited, surprised too as she saw one of the other nets having the tear in it now with the Wysto going towards it. They're here, whatever they are! But the problem is that she has to wait for Abraxas to dispel the invisibility before she can use her spell. She would ready Hypnotic Pattern, waiting to use it once Abraxas dispels the magic and she can see her target.

DM Screen:

Jian vs. Enemy (Disadvantage-Unseen): 10
Grapple vs. Enemy (Disadvantage-Unseen): 9 Enemy Athletics: 9

Enemy WIS Save: 8

The ripple in the water moves closer and closer toward the net, until the net rips, a single tear from bottom to top, releasing the fish inside to the freedom of the ocean. Garu is waiting, lunging with her jian; though the piercing nature of the weapon moves it deftly through the water, she does not feel it strike anything physical. Aisha suddenly drops into the water from above and grabs on to the unseen assailant. Whatever she holds struggles against her grip, twisting and turning her through the water, but she maintains her grip.

From his perch atop the raft, Abraxas sees the struggle and weaves his magic. In an instant, the foe is no longer invisible; Aisha has grabbed hold of a massive crab, demonic in appearance, almost five feet wide with two large pincers and four spindly legs thrashing against her grip. Harmony is likewise prepared, and a dazzling array of colors - placed perfectly to encompass the crab and not her allies - causes the creature to fall limp in Aisha's claws.

Abraxas stares at the demonic crab. "Have I seen anything like this before?" He sorts the mental history of everything he has read about demons and crabs: 23.

Abraxas has never seen anything like this creature. To the best of his knowledge, it doesn't exist on Toril.

Aisha, glad she managed to grab onto it, but somewhat afraid of what it could do to her once it became visible.... was glad when harmony's spell took effect, rendering it unconscious. She would call out to the others saying Help this one get it to the shore, before it awakens! even as she's frantically splashing to get it either in the net, if that was the purpose of the blind, or to the shore, if not.

Athl: 6

Harmony had been surprised that the creature who had been invisible was a massive demonic crab. But luckily her spell worked and the crab had gone incapacitated. She then heard Aisha, nodding back. So she would help Aisha with carrying the crab to either the net or on shore, whichever is better.

I would assume this would have given Aisha advantage on that Athletics check, or should I just do an Athletics check as well?

Athletics: 6

OOC: No Athletics check needed, you just move at half speed while grappling or carrying another creature.

Aisha and Harmony emerge from the water, splashing onto the raft with this suddenly visible - and complacent - crab creature. Still beneath the waters, Garu sees the third net has now ripped, freeing the fish there. The guards there are looking around frantically, but the source of the tear remains invisible.

Abraxas looks at the water and looks at the creature on the shore. "Can we bind it? Tie it up?" he says to Aisha and Harmony. at the same time he hopes to perceive the location of the other demon crab: 9. If he can tell where it is, he will cast Dispel Magic again. If he isn't able to perceive it, he will turn toward the shore and try to help the others control the creature before it wakes.

Touching her holy symbol, Garu steps into a temporary space in the Weave using Misty Step and emerging directly next to the other net then will reach out her arms to attempt to grapple the invisible creature.

Aisha would say to those near Quickly! Bind this one! No matter what else happens, if we can atleast get ONE of them... we can find out morre! We must bind and imprioson it, so that we can question it!

Harmony had heard Abraxas and Aisha, nodding back. "Right!" she said back as she finds some rope and goes to tie/bind up the crab.

Sleight of Hand: 12

OOC: Changing Garu's action for this round to a search, since the creature she is trying to grapple is currently invisible.

Abraxas Perception (Disadvantage-Unseen): Lower of 23 or 5
Garu Perception (Disadvantage-Unseen): 11

Claws vs. Garu (Advantage-Unseen): 22
Claws vs. Aisha (Advantage-Unseen): 18 Damage: 3

Abraxas stares hard into the water, watching Garu reform from mist under the waves, where the third net has ripped. Neither sees the assailant at first, but Garu notices a ripple at the last second and twists away from the creature as it appears, slicing a claw through the water at the Kitsune.

Aisha and Harmony, with no rope in their possession, find that they have no time to search for any. The water beside the raft splashes, and an invisible claw slices Aisha's leg as another of the crab creatures becomes visible.

Turn Order:
Enemies
Players <=====

Placement:
Abraxas, Aisha, and Harmony are atop the raft with two enemies, one of which is incapacitated.
Garu is 45 feet away, underwater.
Aisha is engaged in melee combat with one enemy.
Garu is engaged in melee combat with one enemy.

Tracking:
One enemy on the raft is incapacitated for 48 seconds.

Abraxas would like to try this: he will move 5 or 10 feet closer to Garu and that demon crab (even getting in the water if necessary) and cast Slow on all the demon crabs, including the unconscious one. It's a DC WIS 15.

If that is not possible, he will cast Ray of Frost on the crab closest to him: 18 for 5 damage.

Aisha see's that she's under attack, and draws both her daggers, both of them slashing out in the direction she assumed her assailant had came from, both daggers flashing as they go out. Before casting her spirit of healing. This time, it took on an azure hue, appearing as a water-nymph as it embraced it's creator and mistress. Tsavi, panicking on the shore, but obeying her mistress' orders to not enter the water.

Harmony was surprised as another crab appeared and became visible, attacking Aisha. She will cast Vicious Mockery on the crab attacking Aisha before looking at her. "Stop that thing!" she cheered, giving Aisha bardic inspiration. They have to hurry up and beat this before the other one wakes up.

Action: Vicious Mockery at the crab attacking Aisha - 15 WIS Save or take 3 psychic damage and disadvantage on next attack roll

Bonus Action: Bardic Inspiration on Aisha 

One hand on her holy symbol, the other clutching her jian, she scours the water around her looking for a sign of the creature. “Shine your divine light on this misguided creature”