Soar, you hold the blade in your hand and dip it into the water that Tobin has cleared; the light shines brightly into the depths, and though the radius of its brightest light does not reach tot the bottom, its dimmer light does, and you can see several shiny items.

You also see a creature, floating near the bottom. You can't see it clearly though; it's right at the edge of the radius of the light. Then another drifts into view. It seems to be floating, moving slowly and steadily in your direction.

Bazavur, Soar's sword is very shiny all of a sudden. It's quite distracting.

Tobin, you cast your spells, and freeze the water. As Soar is illuminating the pool, your unseen servant crosses the ice bridge and grabs the gem.

Soar, immediately you (and Varan, whose attention was on the depths) see the creatures, now four of them, react the moment Tobin's magical servant touches the gem. They start to move quickly towards the surface, and you now see them more clearly.  They do not look friendly.

Everyone roll initiative please.

Varan quickly pulls the rope and piton out of the water, "Guys, I think I caught a few things, and they don't look friendly." 

Initiative: 17

Tobin:

As the unseen servant calmly and unaware grabs the gem and starts walking back across the ice bridge, Tobin senses his companions’ trepidation and prepares to act!

Initiative:  3

Soar initiative: 4

Aiwin’s Initiative: 15

I've rolled Bazavur's initiative as 17+5=22.

While the unseen servant is holding the gem and carrying it towards Tobin, the creatures appear to have no interest in it, and I believe unseen servants can't really play any part in combat, is that right?

Round One:
Bazavur, Varan and Aiwin
All the creatures
Soar and Tobin

Feel free to adjust your starting position if appropriate. Creatures C1 and C2 are 35 feet diagonally from Soar and Varan, down in the depths of the pool C3 and C4 are about 10 feet further away. The ice bridge is intact and leads to the surface centre of the pool. It's slippery, but traversible.

Bazavur, Varan and Aiwin are up.

Aiwin sighs as he grabs two more arrows and lets them loose at one of the creatures (C4). As he lets loose the second shot he mutters some words in Eleven that translate for anyone who knows it as ‘explode’.

OOC:

Attack 1: 22 (27-5) Damage: 16 (6+10)

Attack 2: 27 (32-5) Damage: 23 (13+10)

Arcane Shot: Bursting Arrow:You imbue your arrow with force energy drawn from the school of evocation. The energy detonates after your attack. Immediately after the arrow hits the creature, the target and all other creatures within 10 feet of it take 12 (6+6) force damage each.

Dread Ambusher Attack: 14 (19-5) Damage: 22 (12+10)

Using Sharpshooter on all 3 attacks

Varan smirks, "Eh, some excitement now!" He grabs his bow and notches an arrow as he stands at the edge of the pool; and takes aim at the closet creature and fires. He'll then move away from the edge of the water to make room for the heavy hitters.

Action: Fires an arrow at C1, Attack: 27(with advantage due to assassinate), Damage: 12 Piercing(6 Bow + 6 Sneak Attack).
Movement: Moves 20ft back from the water, (four squares down).
Bonus Action: Hide, if possible(cunning action): 12 stealth(natural 1, Varan doesn't feel like hiding at this time, lol).

(Sorry I missed the initiative call. Life got busy)

Hearing Varan call out that he caught something, Bazavur rushes over towards Tobin interposing himself between the gnome and the water. 

“Just stay behind me. We got this.” He says to Tobin trying to inspire him (bardic inspiration 1d6 to attack roll, ability check or saving throw)

Bazavur then stands ready, focused on avoiding any incoming strikes. (Dodge action)

Two vicious hits from Aiwin's arrows, though the third misses.  The force energy catches two other creatures, and C4 looks very hurt.

Varan scores a solid hit too, and moves away, though he doesn't really see anywhere he could hide.

(I think even without the nat 1, there aren't any hiding places here, unless you create one.)

Bazavur gives a bit of cover, and a bit of inspiration, to Tobin.

The creatures are starting some distance away, and so need to use their dash actions to get on top of you. C4 having taken so much damage from Aiwin seems to see him as the biggest threat, and chases some way out of the water - the creatures don't appear to be hampered in their movement outside the pool.

C1 gets into range with Bazavur, and two nasty, jagged claws slash towards him, snapping in the air. However, dodging as he is, he manages to avoid both attacks.

Soar and Tobin are up.

Tobin:

"Oh my oh my!" exclaims Tobin as the lobster-like creatures burst out of the water.  Thankful for Bazavur's protection, the small mage puts his hands together and weaves a complex spell.  A glowing column of magical damage coruscates through the forms of two of the creatures (C3 and C4), battering them with magical force damage!  Tobin looks to step back from the creatures assuming he is not already within their reach.

Order of Scribes Lightning Bolt => Force Bolt:  DC 20 Dexterity for Half:  28 force damage, 14 if saved

(If not engaged with C3, he will back away to the northwest.  If he is engaged, Tobin will stay where he is so as not to provoke AOO).

Soar glares at the monster in front of her (C2). "Pest removal. My favorite thing." She extends her hexblade's curse on it. 

Attack: 12 Damage: 13 plus 4 from hbc

Attack: 18 Damage: 15 plus 4 from hbc

She turns to Tobin. "Should we try to get that gem and get out of here?"

The lightning spell sparks across the water; both creatures fail their saves and take full damage. Tobin, you are in melee range of the creature, so opt not to move.

For Soar, a 12 misses but 18 hits, and C2, previously unhurt, now joins its fellows in pain.

Round Two:
Bazavur, Varan and Aiwin
All the creatures
Soar and Tobin

Bazavur, Varan and Aiwin are up.

Bazavur feels his rage bubbling up inside and lets out a battle cry as multicolored lights twinkle within 10 ft of him. (Plus 1 ac to allies within range). He takes two swings of his newly acquired orange tinted metal glaive at the creature he perceives to be the biggest threat to the rest of the group (c3, 27 and 10 (nat 1) to hit, for 12 and 9 damage respectively)

Aiwin, as there is an enemy within range threatening you, your attack rolls are at disadvantage (unless you have a feature that negates this). Can you give me three additional rolls please?

Bazavur starts to sparkle angrily. He makes a solid attack with his glaive, and then, unused to the weapon's size and weight, misses badly with the second.

(I've marked Bazavur's aura on the map with a purple circle, and also added in Soar's paladin auras in yellow.)

Varan is up, plus Aiwin's extra rolls.

"A little to close for comfort there, ugly." Varan says as the creature gets up in his face. He'll side step around the beast watching its movement; when an opening shows he'll run towards the back of the area. As he moves, he'll take a shot at one of the creatures that appear to be problematic.

Bonus Action: Cunning action, disengage.
Movement: Move the 35ft towards the backside of the pool, hugging the wall of the maze. (ending up at the bottom left of the fourth square to the right).
Action: Fires an arrow at C3; Attack: 24, Damage: 12 (7 piercing + 5 sneak attack)

(I forgot to add my bonus damage from rage to my two previous attacks. So each damage roll should have been plus 2 to what I posted. Also, Tobin I forgot my bardic inspiration also does the following: “If a creature has a Bardic Inspiration die from you and casts a spell that restores hit points or deals damage, the creature can roll that die and choose a target affected by the spell. Add the number rolled as a bonus to the hit points regained or the damage dealt.”)

Tobin:

(apply the Bardic Inspiration to the force damage on the more damaged of the two creatures affected.  1d6 value rolled is 2  ).

Varan edges round the creature, which turns to stare at him, alien eyes unreadable. As he moves away, he shoots another creature for 12 damage, right into the torso.

Bazavur, your extra damage is duly noted and Tobin's extra damage is done to C3, clearly the most injured of the creatures so far.

Still need Aiwin's disadvantage rolls...