Quote from Backstabitha >>

That is a nasty attack! Thankfully it misses Glink. Can he “see” the creatures now (For the purpose of spell targeting)?

 Yes. You can see it due to the flames.

Nib slashes one of the slimes and it splits into two pieces! 

One of the pieces is blasted and pierced by arrows that send it to the bottom, unmoving. The other half ripples and prepares the attack.

Glink Go!

Glink opens fire on the left tentacle, unleashing a barrage of projectiles of pure light, following which Prism fires one too.

(2nd level magic missile for 2+2+2+2= 8 force) boo!
(Attack: 24 Damage: 5 force )

Many bits of the smaller slime are blown into the air but it is still moving about.

Tentacle at Glink Attack: 10 Damage: 7 Bludgeoning plus 2 Psychic damage. Lose spell slots equal to psychic damage.

Tentacle at Vodin Grapple check 16 if grappled, Vodin will be knocked prone and drawn underwater!

Everybody go!

Semnande will try cut down whichever tentacle he can reach.  His blade crackles with sonic energy, hoping to impede the thing's movements.

Booming Blade: Attack: 20 Damage: 7 slashing plus 4 thunder (and 5 if it moves.)

Vodin 

Acrobatics vs Grapple

6 - rolled in game log

Vodin is yanked off of his feet and pulled into the water.

On his turn while holding his breath he tries to break free. 

Acrobatic vs Grapple

25 (Nat 20) - rolled in game log

Once free he will head for solid ground on the stairs moving back 15 ft.

Glink manages to sidestep another tentacle while he and Prism continue firing, focusing on the necrotic, spell stealing tentacle.

Attack: 16 Damage: 6 lightning 

Attack: 23 Damage: 4 force

The small slime is blown apart!

BUT Semnades attack turns the larger one into two smaller ones. 

One moves away from the group and pops but is not destroyed.

The other attacks Semnade Attack: 11 Damage: 12 Bludgeoning plus 2 Psychic damage. Lose spell slots equal to psychic damage.

Everybody go!

Lightning crackles and laser beams pulse as Glink and Prism continue shooting.

Attack: 11 Damage: 8

Attack: 8 Damage: 7

(Notifications have been bugged.)

Semnande scowls as his blade divides the ooze but does not kill it.  He falls back on his magic once more, casting toll the dead.

DC 17 Wisdom Save or take 10 necrotic damage.

WIS save 11

Another small slime is eliminated but there is a fiery trail roaming about the room underwater still. It seems to be trying to stay away from the party.

Vodin tries to skewer the last one with his arrows 

Longbow

Attack: 21 Damage: 9

Attack: 26 Damage: 9

On hit his bees attack as well dealing 2 damage

The arrows float to the surface covered in flickering jelly which eventually stops glowing.

YAY win!!

"Well done Vodin, and your little bees too." Nib says, brushing himself off and ending his rage.

Semnande takes a few steps back, scowling.  His hands glow as he holds a healing light over the spot on his chest where the ooze hit him earlier.

"Does anyone know what that was?  Or where we even ended up?"

Healing Hands: 6

“Glowing tentacle slime,” says Glink with a nonchalant shrug. “Ya need a minute there Bud?” he asks before heading out.

(Any of those tentacle attacks would have 1-shotted poor Glink but for now he remains unscathed)

Semnande shakes his head.

"No, I just need to pay more attention."