Jorzu 

Slap! The nugget whacks Jorzu in the face. Its legs scramble to latch on but it overestimates the size of his head and fails to take hold. He stumbles back a step and shakes his head to clear the stinging feeling. He uses Byrony's attack as an opportunity to disengage and retreats several feet (20ft to be precise). 

Bryony continues to assault the gemmule that attacked Jorzu.

Shortsword: 12 to hit for 10 piercing damage (I am unsure if that hits or not so I'll roll the dagger attack as a straight roll without Vex. If this first attack hits, I can roll again for adv on the dagger attack).

Dagger: 19 to hit for 3 piercing damage

(Will roll sneak attack only if the target did get Vexed and I get advantage.)

Spurred on by Fergus’ encouragement, Quinn attempts to smash this nugget once and for all. He rains down two heavy hits with his magical mace. 

Attack 1: 17 to hit for 15 damage

Attack 2: 14 to hit for 9 damage. 

DM: If the first hit kills his target, Quinn will run to Fergus and attempt to rip the nugget that latched on to his throat. 15 STR check to pull thing off of Fergus. I used my bardic inspiration for this STR check.

Jorzu narrowly dodges the probing alien leech, and backs up to the far corner of the dwarven living room.

Bryony manages to nick it with her dagger, but it is still far from defeated. (19 hit; 12 did not. Its AC is 14.)

In the other room, Quinn manages to crush gemmule #1 with two blows of his magical mace, killing it. (But he is unable to help Fergus quite yet...)

Fergus feels sharp alien probes entering his face, drawing blood from the wound. He takes 7 piercing damage.
Then it strikes at him again with a wave of pure psychic force:

Gemmule #3 Psychic Slam Melee Weapon Attack vs. Fergus: 24. Hit: 8 psychic damage.

Another one strikes at Bryony in the other room:
Gemmule #2 Psychic Slam Melee Weapon Attack vs. Bryony: 16. Hit: 23 psychic damage.

It likewise tries to attach to her shoulder. Bryony: make a DC 14 Dexterity saving throw. On a failed save, the gemmule enters your space and attaches to her. 

Fergus, Boona, Jorzu, and Jurgen may act next. Boona and Jurgen have to descend 20 feet of rope (40') plus 10' on either end, to reach the closest gemmule (attacking Bryony). They may Dash without attacking, they may jump (2d6 bludgeoning damage unless you can mitigate) and attack, they may make a ranged attack from above, or they can go halfway down the rope and make a ranged attack with disadvantage (from hanging from a rope), or they can try something else.

Jugen dashes down

Jorzu 

Safely put of reach, he hopes, Jorzu stares at the tiny face sucking critter. He strings a curse together that he hopes will stick, "No more faces you will suck. Strength begone with some luck". He squashes two beads together as his curse is spoken and then sends two balls of Force energy at the gemmule attacking Byrony. 

BA - casts Hex on the gemmule, targeting Strength in hopes of allowing people to more easily remove them.

A - casts Eldritch Blast at same gemmule

Blast Attack 1: 18 Damage: 11 + 1 from Hex

BlastAttack: 21 Damage: 9 + 3 from Hex

Boona looks at Carp, " Stupid voice in my head again....."

She looked towards the hole and the emerging noises but stayed put guarding the boys.

Fergus:

Feeling his vitality sap out of himself even after his powerful spell, Fergus casts a healing spell to try and keep himself upright as the creature again lands multiple attacks on him.  "Anytime, Quinn," he says urgently, sending another wave of encouragement his friend's way (bardic inspiration 1d8) as he tries once more to shove the thing off his face!

Cure Wounds level 2 to heal himself:  28

DC 14 Dexterity or Strength save for flesh nugget to not get shoved off Fergus' face!

Jurgen swings down on the rope, getting within melee distance of Bryony's attacker. Boona stays above, and continues to converse with and monitor the two boys, who creep ever closer to the edge of the hole to watch.

Jorzu hexes the leech in front of Jurgen and Bryony before unleashing a pair of potent black beams at the little alien creature. The arcane energy rays nearly tear it apart. (It is still alive, but barely.) He can feel his extra eyeball twitching wildly under his scarf.

Fergus heals himself and inspires Quinn, before trying again to rid himself of the painful parasite on his face. Gemmule DC14 Dex Save: 12

Bryony should also make a DC 14 Dexterity saving throw, as she tries to dodge her own hungry leech.

Quinn and Bryony are up next!

(Fergus successfully manages to tear the hungry thing off his face.)

Bryony manages to avoid the gemmule trying to attach itself to her, but the psychic blast sent her reeling with pain. Her head felt like it was a vise grip. The halfling rogue attempts to finish off the gemmule harassing her.

Shortsword: 17 to hit for 7 piercing damage

Dagger (Vexed): 21 to hit for 5 piercing damage

Sneak Attack: 17 piercing damage!!!

Quinn pounces on the nugget that Fegus ripped off his throat. It strikes down at it with two heavy blows. 

Attack 1: 14 for 10 damage

Attack 2: 14 for 19 damage

Target is sapped and has disadvantage on next attack roll. 

Bryony manages to slash her attacker to pieces. Another one killed.

Quinn gets in a fresh one-two slam with his powerful mace, bloodying the final gemmule, now freed from Fergus.

It turns on Quinn now:
Psychic Slam Melee Weapon Attack vs. Quinn (sapped): 16 Hit: 15 psychic damage.
Leech Bonus Action: Quinn must make a new DC 14 Dexterity save. On a failed save, the gemmule enters his space and attaches to his throat.

Then, Fergus, Boona, Jorzu, and Jurgen may act next!

Fergus:

Still recovering from his unanticipated close encounter with the alien creature, Fergus slides over and does his best kick-ball-change at the flesh nugget--with the emphasis on KICK!

Bardic Agile Strike:  Attack: 20 Damage: 9

I’ll post pending DM’s judgment on hit roll by the gemmule. 

Quinn’s dex save: 19

Quinn dodges its attempt to attach to him, and mentally shields himself from psionic blast, as well.

Fergus gives the thing a powerful kick, sending it slamming into a wall. It is significantly injured.

Jorzu, Jurgen, and Boona may act!

Jorzu 

"Well done Byrony! " exclaims Jorzu as Byrony's flashing blades brings down her gemmule. He hot foots it towards the door to the shrine room. He enters and steps to the side to keep the doorway unobstructed. Scanning the room he spots the final nugget. The twitch on his neck gets more fierce. He absent-mindedly scratches at it and moves his fur collar just enough that the eye can see the room.

If the eye does nothing but look: He sends 2 Force balls at the little alien.

If the eye does something unusual: ????

M - moves to the square just E of the doorway inside the room

BA - transfers Hex to the final nugget

A - Eldritch Blasts if the eye does nothing

Attack: 10 Damage: 7

Attack: 15 Damage: 8