Quote from RodTheBard >>

 

Sterling casts Vicious Mockery as soon as he sees the drow. DC 14 Wisdom save to avoid, otherwise he takes 1 psychic damage and has disadvantage on his next attack roll.

(Someone can still use Oriace's Bardic inspiration for a spell damage bonus of 1d6 if it does do damage.)

*raises hand*

(( Seems like as good a time as any, so yeah, if the VM hits: an extra 5 psychic damage. ))

(Yeah,  not sure why I have it in my head that a rapier is a light weapon.   My bad.)

Toser moves to follow after the drow.   As he emerges from the darkness he casts Minor Illusion

The sound of marching feet can be heard from past where the drow is, from the direction the drow is headed. 

Toser then yells "It's the Watch!  Stop"

Quote from cyreon >>

(I think we don't get AoO because none of us can see in the magical darkness, and seeing the target is a requirement for an AoO. I suppose the drow only moved away and didn't dash with a BA. If he did dash, Oriace will only dash after him and not attack.) 

 Very true. I forgot that part of the rule. I thought it was just subject to the disadvantage of not seeing them (as you would still hear and feel). But I suppose that would be reacting after they move not being able to intercept as you anticipate 

Seeing the inky sphere engulf the group followed by the fleeing Drow, Mana is slow to leap in front of him to prevent his escape. As the others emerge from the darkness, Mana leaps out of the shadows and darts in front of the Drow to interpose himself from the perpetrator’s escape route. He hisses another curse, this time looking up into the Drow’s face from roughly navel height to the Drow.

Again in Undercommon, Vicious Mockery in a squeaky Goblin accent,

”Dos ph’natha fallkiper ulu dosst clarg’arth!”

 (DC 14 WIS save or 1 psychic damage and disadvantage on his next attack roll.)

With a bravery he didn’t know he had, Mana (free action) draws his rusty rapier and mimics en guarde.

[Sorry for being out of touch that long, no excuse.]

[[Sorry for the deleted post, I was literally looking at the wrong character.]]

Wagner moves out of the dark and tries to follow the drow to take him down.

(Move, then attack if in range. Wagner will use misty step as a bonus action if the move is less than 30 ft short, or dash if it is farther than 30 ft.)

Attack: AC 20, 9 piercing damage.

This round the only attack that hits (both vicious mockeries were saved against, even with Bane) is Wagner (the drow was only 30ft away at first). Hearing "the watch" approach, the drow instead shouts some words and then becomes almost weightless, floating up to the roof of the adjacent building (20ft high) and continuing to flee. He is now 50ft away from everyone who was in melee (if anyone didn't go back into melee after leaving the darkness, you would have been 10ft away so now 60ft). They are barely visible (three-quarters cover, but still line of sight)

(Assuming Mana gets to hack at the Drow’s ankles as he lifts off as an opportunity attack, he uses his reaction to do just that. Attack: 13)

Mana leaps upwards trying to time the swing of his rapier with the apex of his jump. His slash finds no purchase on the floating Drow.

He holds his concentration for Bane in hopes that one of his mates has a spell that can halt the fleeing foe, or at least hinder the Drow if he retaliates during his exit.

He spits one, perhaps, final curse at the Drow, this time in Common (Vicious Mockery DC 14 WIS save or 3 psychic damage and disadvantage on his next attack):

”Your misshapen face is known. Your fate is sealed!”

Yes, I did mean to say take AoOs (actually can this time)

As the drow begins to float upward, Oriace seizes the opportunity. With a quick, fluid motion, he lashes out with his rapier, striking true against the drow’s side. The blade bites into his flesh just as he rises, drawing blood and eliciting a sharp hiss of pain (Hit 23 for 8 damage). "Not so fast!" Oriace growls, his voice low but laced with a magical edge. He focuses his energy, channeling his magic through his words. "Run while you can, but your cowardice will be your undoing!" The vicious mockery courses through his voice, aiming to further weaken the drow’s resolve and throw him off balance as he tries to escape. 

(Vicious Mockery DC 14 WIS save or 3 psychic damage and disadvantage on his next attack.) 

Toser watches as the drow suddenly levitated and rose into the air.   He realized he wasn't close enough to do anything more and could only stand and watch the drow escape. 

"He's getting away!" the would-be jeweler screamed in his head as the drow started to flee. Sterling's companions tried to finish him; if they could just take the assassin down before it was too late...

"That's right, run! It figures you're too much of a coward to even finish your job!"

ACTION: Cast Vicious Mockery, targeting the drow. DC 14 Wisdom save or he takes 3 psychic damage.

OA: AC 13, 10 damage.

Wagner disappears in a puff of smoke, reappearing on the rooftop. (BA misty step)
He runs over to the drow and stabs at him with his rapier. (AC 11, damage 7)

Two of the vicious mockeries hit (Mana and Sterling) as well as Oriace's AoO. 

Realising he can't escape, he positions himself somewhere he can't be seen from the ground, and swings twice at Wagner. 23 to hit for 9 damage. And then a nat 1. 

(Oh dear. Was that 23 from the Drow at disadvantage (vicious mockery) and -4 (bane)?)

Mana will attempt to Dash up the side of the building (60’ total).

Acrobatics: 24

(Yes. Though just -1d4 which in this case was a 1. I rolled an 18 and a 19)

Mana can make it up the building, and part way to the Drow.

Oriace hurries after Mana but instead of putting everything in it, he continues to insult the drow. (Not sure if hearing them fight is enough or if they have to actually speak.)

Acrobatics: 20
Move: move towards 5ft? and 10 ft up the wall. 
Action: Vicious Mockery for 4 damage unless WIS DC 14
BA: last Bardic Inspiration to Mana for a spell or whatever he wants to use it for.

“Wagner! Are you still inspired?”

Mana gave Bardic Inspiration to Wagner earlier in the fight, thinking he would use it to continue to try and grapple. Unfortunately, he has quite forgotten if Wagner used it to attack earlier. He will re-Inspire him as a bonus action next turn. (Sorry for losing track.)

Sterling rushed to be as close to the sounds of Wagner's conflict with the drow as he could be. He wasn't exactly a skilled athlete, and had no magical means of getting onto the roof; the best he could do was to be close in case the assassin jumped (or fell) back down.