As far as you can tell, he is alone. He fails (and so I now need to try remember to remove 1d4 each time)

Oriace grits his teeth as the drow’s first strike connects, pain shooting through his side. The second swing, thankfully, glances just past him as he twists out of the way. This drow is more skilled than he anticipated, and the confidence in his enemy’s eyes only sharpens Oriace’s focus. Feeling the weight of the battle pressing in, Oriace shifts his stance, readying his rapier and bringing his free hand up for balance. He knows this fight will require more precision and caution. 'This one’s too skilled,' he thinks. 'We need to wear him down.'

He concentrates on dodge-ing and parrying. "Stay on him!" Oriace calls to his companions, his voice firm despite the sting of the wound. "We’ll take him down together!" As he dodges incoming blows, Oriace taps a lively rhythm with his feet, creating a pulsating beat that resonates through the air in the alley. “Feel that heartbeat, my friends!” he shouts, his voice rising above the clash of steel. “Let it guide your strikes! Together, we’ll turn this battlefield into a performance!” (1d6 Bardic Inspiration for the first player who rolls an attack roll!)

"You're not going to hit me again!" Oriace announces, hoping to taunt the drow with his words into attacking him again. He braces for the next attack, knowing that if they can keep the pressure up, they’ll find the moment to turn the tide.

Toser watches as the drow deftly strikes out at Oriace.  As the blade is about to bite Toser chants a few words in gnomish and the drow is magically distracted.

Reaction - Silvery Barbs - Grant myself advantage on next roll, drow must reroll attack d20 and use lowest number

Toser then darts in himself, emboldened the actions of the others and draws his rapier and a dagger and attacks!

Action - Attack: 12 Damage: 7 with rapier

BA - Attack: 23 Damage: 4

Add bardic inspiration from Oriace 4 to rapier attack

"We need an edge," thought Sterling as he quickly uttered an incantation, focusing on the drow. He then drew his blade and rushed into the fray.

ACTION: Cast Faerie Fire, targeting just the drow's area, if possible (DC 14 DEX save to avoid)
FREE: Draw rapier
MOVE: To within 5 feet of the drow

End of turn!

(-1d4 to that DEX save)

Toser manages to turn the hit into a miss (Oriace takes no damage, but he did see the blade skim his side and got some phantom pain expecting it to hit). He then misses (even with the bardic inspiration) though his bonus action hits.

Dex save: 2 

Wagner is up (with advantage if the above roll is less than 14)

Ping

Attempted resurrection from page 9 of the forums.

Wagner, now he has advantage and hunters mark cast, will attempt to attack with his rapier.

Attack: 18 (just hits) for a total of 17 damage (including hunters mark)

The drow grimaces in pain and takes two retaliatory swipes at Wagner. Both miss (even without the -1d4. Though one was close).

Everyone is up!

Still from the shadows, Mana looks quickly to the civilian to see if they are fleeing/aware of the attack/in further need of assistance. He maintains concentration on the Bane spell, but spits out a new curse (Vicious Mockery) at the Drow in Undercommon. (DC 14 WIS save -1d4 from Bane or 1 psychic damage, gotta work on my insults)

”Dosst ‘ranndi l’amithe tluin ju’zhasus pholor a natha bulette!”

Toser presses the attack with both of his blades.

Action - Attack: 12 Damage: 6 with rapier

BA - Attack: 9 Damage: 3

(( @Paladin53 - don't forget, with Faerie Fire active, you get advantage on both of those attacks. ))

(Oh, and @Wagner has a Bardic Inspiration for the next 9+ minutes)

Closing in, Sterling took on an unusual but deceptive stance, then spun into an attack on the drow.

"Now, Wagner, we've almost got him!" he yelled towards his companion.

ACTION: Attack the drow
* Rapier Thrust - Attack: 14, Damage: 10 Mundane Piercing (plus 1 more on a crit)
BONUS: Grant Bardic Inspiration (1d6) to Wagner

End of turn!

(( I missed Wagner getting BA... Sterling will give his to Toser, then. ))

"Now! We've almost got him!"

Quote from RodTheBard >>

(( @Paladin53 - don't forget, with Faerie Fire active, you get advantage on both of those attacks. ))

 Second rolls for advantage

Attack: 20

BA - Attack: 23

Seeing how the Draw is encircled by his companions, Oriace joins in the offence and attacks with his rapier.

A: Attack 17 (incl. advantage, which I believe just misses)
BA: Bardic Inspiration to the next attacker with a spell (remember that you can add it to spell damage)

The drow almost succeeds against the Vicious mockery (15 -3 for Bane).

Toser then manages to benefit from the Faerie Fire to get a solid hit in (just realised now you are using a rapier. You can't do Two-Weapon Fighting unless the first weapon is light, which a rapier is not. It would need to be a shortsword instead, or the dual wielding feat)

The other attacks do miss. Wagner attempts to continue with attacking with the rapier. 20 to hit, 8 damage.

The drow starts to look injured (below 50%) and so looks around, and suddenly it becomes dark as the drow casts darkness (which from reading, I think also disspells the Faerie Fire as it is a spell less than 3rd level that has created light). The drow then starts to move away. Everyone in melee gets an AoO with disadvantage (unless you have a way of seeing in magical darkness) Wagner misses this (15) 

Anyone who didn't reach melee (just Mana?) will see them emerge from the darkness and try and flee the opposite direction of the original quarry (who has started to run to cover and hide). He ends his turn about 10ft past Mana (assuming Mana stayed 20ft away originally) 

(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.)

Oriace cries, "He's trying to get away! After him, friends!" And he follows the sound of the drow's footsteps until he re-emerges from the darkness. "He's here! Someone get a hold on him!" He yells and attacks again with his rapier. 

Action: 7, rerolled with halfling's luck! It Change to 12 :/

The would-be jeweler grit his teeth as he recognized the spell creating the enveloping darkness, negating his own magic as it did.

Quote from cyreon >>

"He's here! Someone get a hold on him!"

Following Oriace's voice, Sterling carefully moved through the darkness until he could at least get a glimpse of everything in the not-quite-so-absolute darkness of the alleys. Not wanting to waste anymore more magic trying to highlight the assassin, he instead launched into a scathing rebuke.

"You imbecile! Murder? Really? You're THAT scared of an honest day's work instead??? Pathetic!"

Sterling casts Vicious Mockery as soon as he sees the drow. DC 14 Wisdom save to avoid, otherwise he takes 4 psychic damage and has disadvantage on his next attack roll.