Acrobatics check 1: 20

Acrobatics check 2: 20

Con save: 20

Pud shakes his head as is vision returns. He spots the two darklings attacking Titaani and casts acid splash at them. He then commands Rizzo to blast the creature fighting Elkhorn. As he unleashes the attacks, Pud Shields his eyes with his magical shield. 

Action: acid splash targeting the two darklings fighting Titaani. Dex save 15 or take 8 acid damage.

Bonus action: force blast from Rizzo at the darkling fighting Elkhorn. 18 to hit for 6 force damage.

Ben:

Not terribly concerned about the approaching darklings (though perhaps he should be), Ben rushes up the spiral staircase to confront Creeping Lyn!

(Move and Dash)

Titaani retains her vision – barely – but is once again restrained by a darling. (She still has an action – either to make a new contested attempt to break the grapple, ot to do something else.)

Ben races up the spiral staircase to the top level. He cannot yet see Endelyn, but knows she must be very close.

Pud takes on the darklings on the stage harassing Titaani:
Darkling 3: DC15 Dex Save: 19 or take 8 acid damage.
Darkling 5 (wounded, grappling Titaani and warily watching Amidor): DC15 Dex Save: 17 or take 8 acid damage.
...While Rizzo blasts the other one nearby, engaged with Elkhorn. It is quite visibly wounded, but not down yet.

Matilda, Horatio, and Titaani (grappled) may act next!

Titaani is freed, but Darkling 5 combusts. 

Amidor: DC10 CON save or be blinded: 12
Pollenella: DC10 CON save or be blinded: 8
Titaani: Make yet another DC 10 Constitution saving throw or be blinded until the end of your next turn.

Matilda, Horatio, and Titaani may act next!

Knowing this will likely be the last thing she ever does Matilda throws her magical dagger at Lyns back then races in and stabs up twice with her shortsword.

Thrown Attack: 17 Damage: 9 + 2d6 Sneak Attack

Attack: 12 Damage: 7

Action Surge-

Attack: 19 Damage: 9

SA- 4

Con save: 20

Large Horatio runs up to Titaani and begins smashing whatever enemies are attacking her (( the nearest to her )). 

(( Movement 30' ))
(( Attack 1: Unarmed Strike: To Hit = 21, Damage = 12 = 7 + 5 from Giant's Might ))
(( Attack 2: Unarmed Strike: To Hit = 21, Damage = 8 ))
(( Bonus Attack: Dual Weapon / Unarmed Strike: To Hit = 22, Damage = 12 ))

As he strikes, he yells, "Titaani, I have the scepter, where are the others?"

Feeling overwhelmed, Titaani shakes her head to clear it. Looking around, she realises with a sickening feeling that she has no idea where half of her friends are. That is, until Horatio swoops in.

"I don't know! I need to find the rest of our friends," she calls out to him. "You deal with the darkling attacking Elkhorn. I'll try to deal with this one." 

Titaani faces the darkling directly in front of her, and, clutching her crystal, calls on Titania's power. For a moment, the little gnome seems far more frightening, her eyes going purple and her voice changing to be darker, harsher. "Tremble, for you do not know whose servant it is that you are attacking."

(Action: fey presence, the darkling in front of Titaani needs to make a wisdom save or be frightened until the end of my next turn)

Matilda's sneaky dagger strikes the hag but glances off her thick layers of elaborate costuming. (Just missed her AC!) Matilda's blade, however, finds its mark – twice – as she closes the distance. Endelyn shrieks with pain and fury; she is looking considerably wounded, and very angry.

Titaani again avoids being blinded by the most recent flash.

Horatio finds he can't quite reach the stage yet (not enough movement), but he can (just) reach Elkhorn's attacker.
He pulverizes it. It is consumed in another brilliant flash.
Horatio: Make a DC 10 Constitution saving throw or be blinded until the end of your next turn.
Elkhorn DC10 CON save: 20

Titaani draws upon her fey connections and attempts to scare the other darkling away:
Darkling DC14 WIS Save: 14

Endelyn spins and snarls at Matilda. Her little set of extra arms come out. "Foul little waif!"
Puppeteer's Lash: 9. Hit: 19 psychic damage, and Endelyn telekinetically tries to throw her over the railing into the lightning-charged machine.
Then she spins and strides toward the far end of the balcony, coming face-to-face (albeit 10' distant) with Ben.

Below, Glister runs west along the edge of the Orrery. Ben can just see her at the bottom. She tries to fire another sun ray at Endelyn, although she doesn't have a clear shot (3/4 cover):
Sun Ray: 19. Hit: 12 radiant damage, and Endelyn must succeed on a DC 13 Wisdom saving throw...

Titaani's attacker runs off, terrified by Tiaani's dark visage. It tries to race downstairs toward the stage workshop below. (Pud may have an opportunity attack if he wishes.) 
Elkhorn avoids blindness. (Horatio must still roll.)
Matilda just manages to avoid being thrown to her doom.
Glister's sun ray widely misses its mark.
Elkhorn and Amidor spin and look, ready for any fresh waves of assault.

The darklings swarm Glister. Four of them try to grapple her, even though Glister is a trained circus acrobat:
Darkling #7: STR check: 8 Glister's contesting acrobatics check: 28
Darkling #8: STR check: 0 Glister's contesting acrobatics check: 18
Darkling #10: STR check: 7 Glister's contesting acrobatics check: 12
Darkling #11: STR check: 18 Glister's contesting acrobatics check: 10

Everyone may act! Horatio has a CON save to make, first, and Pud may have an opportunity attack on the fleeing darkling if he chooses.
There are no other aggressive darklings on the amphitheater floor. Horatio, Titaani, and Pud watch as the last of them jump through the hole in the balcony mirror, where Ben and Glister disappeared from view. The other darklings stand uncertainly in the stands, and watch the unfolding scene with fear.

(No opportunity attack for Matilda, as she used her bonus action for her second weapon attack.)

Matilda dashed up to Evelyn, sheathed her shortsword and leapt onto her grasping her dagger and tugging downwards roughly. She then leapt over Lyn giggling as she slipped behind Ben.

Attack: 22 Damage: 8 ( +2 dam for Dueling)

Fancy Footwork ( No AoO).

Ben:

Stepping up to the hag, Ben attempts to smite her, saying, "Here ends the tale of Creeping Lyn, an old washed-up actress has-been."

Longsword Attack 1, Smite Level 1 on hit:  Attack: 19 Damage: 15

Longsword Attack 2, Smite Level 1 on hit:   Attack: 26 Damage: 16

(added d8 if she counts as a fiend:  1  8 )

Pud swings his heavy walking club at the fleeing darkling. He then conjures up an arcane bolt of fire and hurls it at the same target.  Pud shields his eyes and turns to run towards the darklings fleeing into the mirror.

”Guys! Into the mirror after them. That’s where Ben went!”

AoO: 21 for 1 damage.

Action: cast fire bolt 14 for 16 fire damage. 

Move: Run full speed after the darklings heading into the mirror. 

Horatio, fueled by an inner silent fury, shrugs off the blinding attack (( Con Save dirty 20 )). Hearing Pud's proclamation, he makes sure Titaani is able to follow ( he can carry her if she is injured ), but rushes to the mirror. "Titaani, are you okay? We have to get to the others now!"

Matilda and Ben both manage to sink blades into the fleeing hag. Seriously wounded, she gives a pained smirk to Ben. "You can't kill me, boy. Each of us gets to play the lead in our own tragedy, and if you can’t be bothered to put on a good show before you die, don’t waste my time.”

Pud manages to wing the fleeing darkling with his club, but it gets away before he can cast his firebolt. Dashing, however, he reaches the bottom of the center stairwell.
Horatio just beats him to it, managing to climb the first few stairs. Elkhorn, Amidon, and Pollenella follow.

Inside, Glister disengages from the darklings trying to grab her and makes a run for the other end of the room.

Titaani is up next!

"I'm ok! Just a little overwhelmed," Titaani replies to Horatio. "Wait up!" 

(Titaani will use a dash action to get up to where Horatio is)