The Trials - All-Four-One

The Aboleth opens its three eyes simultaneously, and stares intensely at Jury: "COME... MY... MINION"

-> Enslave ({DC 14} WIS saving throw: 26). The foul charm has no effect on Jury.

END OF INITIATIVE ROUND 2

INITIATIVE ROUND 3

26. Charles 
22. Drago 
20. Grixx - affected by Phantasmal Force; 
19. Lair - Phantasmal Force damage occurs in this turn;
16. Jury - concentrating on and affected by Haste.
15. Pale Elf 
12. Aboleth - concentrating on Phantasmal Force

UPDATED MAP:

 (Charles, Drago, and Grixx are up next)

Drago uses another valuable spell slot to dispel magic thus freeing Grixx from his illusion and bringing him back to reality.  He flies over to Grixx(10 ft of movement) and asks for the Potion of Water Breathing "With my precious Periapt of Health and my advantage against being charmed I believe my chances against the monster in the deep are as good as any of us.  The two of you can handle that frost elf is he decides to return."  Drago uses the rest of his action to position the broom as high over the spot that Jury went down as he can.  He prepares to drink the potion (next round, I have used my action this round) and will then dive into the water to find Jury and the monster.

Charles will take his two shots at the Pale Elf. (I'm assuming at disadvantage cause it's dark)

Attack: 17 Damage: 8

Attack: 22 Damage: 12

Grixx sees Tempus vanish.

"What?!  Tempus!  Thank you for another chance!  I will not fail you!"

Grixx looks around at his surroundings.  Drago then appears on the broom asking for the underwater potion.  Grixx doesn't even know about the monster underwater so he will hand the potion over freely.

Grixx then look down at his sword and and then to the Pale Elf that seems to be what he is supposed to kill.

"You will see I am worthy!  TEMPUS!"

Grixx will use Bonus Action to unleash the battlecry of Zealous Presence granting everyone within 60 feet of Grixx that can hear(IMPORTANT: not sure if Jury can hear me underwater) you gain advantage on attack rolls and saving throws until the start of Grixx's next turn.

Grixx will then use Dash to move to AH, -1.

(@Superbad: If you don't have a light source, yes, you'd be attacking in the dark).

Charles quickly presses his trigger twice. The first bullet whizzes by the Pale Elf, but the second finds purchase on its shoulders (Pale Elf - CMD: 34).

LEGENDARY ACTION (end of Charles' turn)

The Aboleth attacks Jury:

-> Tail Swipe (melee weapon attack with reach) vs. Jury:  Attack: 13 Damage: 13 bludgeoning.

-> Jury protects himself in the last minute, casting Shield.

(OOC: Rolling a {DC 13} WIS save for Charles retroactively: 18 - alright, he's fine)

WIS saves for Drago and Grixx:

Drago: 24
Grixx: 19
Both feel no different then a moment ago.

Drago dispels whatever magical effect had overtaken Grixx, collects the magical potion from him, and prepares to dive from up high.

Grixx, in turn, yells from the top of his lungs, finally ready to join the battle and, at least in his head, pardoned by Tempus (Jury is not affected as he is out of range). He then runs forward, wet sand traveling everywhere from his heavy steps. 

LEGENDARY ACTION (end of Grixx's turn)

The Aboleth probes again: "WELL... DEFENDED... BUT... FOR... HOW... LONG?"

> Tail Swipe (melee weapon attack with reach) vs. Jury:  Attack: 28 Damage: 17 bludgeoning. The second swipe is even stronger than the last, but the warforged's shield protects him again.

LAIR ACTION

The water in the eastern portion of the room begins to agitate, and a portion of it surges outward in a grasping tide.

STR saving throws {DC 14}:

Grixx: 16
Charles: 21

Both warriors are able to keep their footing, using the sand's stickiness to their advantage.

(Jury is up next)

First, the soft touch. Necrotic energy rots part of the Aboleth's body away. The foul water becomes even fouler with so many undead and rotting pieces floating around Jury (Aboleth - CMD: 34). Then, the heavy touch. The swing of the staff is slowed down considerably by the water. It will take some getting used to for Jury to swing his weapon efficiently underwater.

Jury also notices that the goo that has been present in this entire lair is thickest immediately around the ancient creature. The warforged reckons this would be quite debilitating those he refers to as "flesh bags."

The Pale Elf turns to face Grixx, now just a few feet behind him, and puffs some wind as if blowing a candle (Grixx's STR saving throw {DC 16} vs. Gust of Wind: 20). The barbarian is pushed 15 feet backwards by a strong wind blowing against him, landing on the water. 

The Pale Elf also stops moving, staying his ground at least for now.

LEGENDARY ACTION (end of Pale Elf's turn).

Felling a disturbance on the water, the Aboleth will try to pinpoint its source.

-> Detect: perception check: 13. 

The Aboleth swims quickly towards the southern tip of the island (moving diagonally and efficiently). Grixx hears the voice in his head once again: "I... HAVE... BEEN... WAITING... FOR... YOU!"

-> Enslave ({DC 14} WIS saving throw: 9): Grixx cannot not help but feel like the Aboleth's will and that of Tempus is one. (Grixx is charmed by the Aboleth, is under the Aboleth's control, and can't take reactions. Also, the Aboleth and Grixx can communicate telepathically with each other over any distance).

-> Grixx’s first order is to approach the Aboleth. In a moment of doubt, Grixx wonders if he really wants to do as told (Grixx is using his inspiration die to reattempt the save: 9 - The real Tempus must have intervened. Grixx won’t fall for the Aboleth’s trickery this time).

(@All: Please note that at this point no one knows that Grixx is enslaved, s please act accordingly).

(@Ori: an attack of opportunity is triggered for Jury after the Aboleth's move, if you wish to use your reaction this round for such purpose).

END OF INITIATIVE ROUND 3

INITIATIVE ROUND 4

26. Charles - benefiting from Zealous Presence for one turn;
22. Drago - up high above Jury's last known location but is unaware that the Aboleth has moved, benefiting from Zealous Presence for one turn;
20. Grixx - affected by The Aboleth's Enslave feature; 
19. Lair
16. Jury - concentrating on and affected by Haste.
15. Pale Elf - concentrating on Gust of Wind
12. Aboleth

UPDATED MAP:

(Charles, Drago, and Grixx are up next).

((Good thing Charles has an action surge, he can reload then shoot the Pale Elf to death! The advantage cancels out the disadvantage! Woo!))

Action: Reload the pistol with normal ammunition.

ACTION SURGE!

Firing two bullets at the Pale Elf.

Attack: 12 Damage: 6

Let's do this one with sharpshooter, cause why not?

Attack: 17 Damage: 19

Drago drinks down the potion that he was able to get from Grixx and then launches himself into the water from 20feet up.  The broom will wait for him to reappear and say it's code word.  Drago moves down as fast as he can and tries as hard as he can to find Jury and the monster that is in the deep.

(OOC: @Lerus Let me know how this search is supposed to go.  I assume he can see some things but, as you say it is hard to find anything.)

Grixx now having a clear mind.  Grixx's emotion takes over and flow through him.  He will feed the blade!

Bonus Action:  Grixx would like to rage.

Grixx will charge up to the Pale Elf, his fury returned and his greatsword held high!

Grixx will make two reckless attacks on the Pale Elf.

1st Attack

Attack:  22 Slashing Damage: 10

Divine Fury:  Radiant Damage:  10

2nd Attack

Attack:  20 Slashing Damage: 10

Charles reloads his pistol. As he does, he feels the Pale Elf's calling to him somehow (WIS saving throw {DC 13}: 20). Whatever it was, Charles ignores it.

He then shoots at the Pale Elf while inspired by Grixx's battle cry. Both bullets hit the elf's chest, but he seems to suffer less from their impact that the sharpshooter had expected (Pale Elf - CMD: 49).

The Pale Elf then spits some nasty sounding words towards Charles.

-> Frigid Rebuke (Charles CON saving throw {DC 16}): 18. Once again, the gunslinger ignores whatever magics the fey is aiming at him.

-> Concentration checks for Gust of Wind {DC 10}: first bullet - 5, second bullet: 12.

(@Laserwhit: Your action was to drink the potion and falling counts as part of your movement. Let's say that you reach 15 feet below the surface with your dive. Next round, assuming you are still trying to find the Aboleth, you'd have to perform the search action. If you want to move to Jury, you'd still have 45 feet to go and underwater counts as difficult terrain, so you'd move only 20 feet and would likely need to dash to get at least near the necromancer).

Drago dives, letting gravity aid him in reaching as deep as possible. His newly formed gills allow him to breath underwater with no extra effort.

LEGENDARY ACTION (end of Drago's turn).

Feeling another disturbance on the water, the Aboleth will try to identify its next target.

-> Detect (perception: 17).

-> Drago is also in the Pale Elf's range as he dives, so (WIS saving throw {DC 13}: 24. He feels nothing.

Infuriated for not having a chance to glorious battle yet, Grixx lets out an enraged yelp (Rage) and starts to move. Unfortunately for the barbarian, both the water and the sandy beach are hard to move through (difficult terrain) and the strong wind from the Pale Elf's Gust of Wind make it even harder to approach. Although he is still a good 15 feet away from his foe, Grixx's is already ready to strike the elf in case he decides to approach himself or the wind stops blowing.

(@Grx: You cant reach the elf this turn unless you dash. I went ahead and made a DM decision there for readying the attack since you had already rolled).

(Lair is next)

LAIR ACTION

Enraged by failing to bend the will of yet another prospect, the Aboleth will let its wrath be know to those that have invaded its watery lair. A large portion of the pool momentarily becomes a conduit for the creature’s rage. 

WIS saving throw {DC 14}:

Drago:15; 
Jury: 8.

The sorcerer takes 2 psychic damage. The necromancer steels his mind and avoids the mind torpedo.

(Jury is up next)