Robin would have cast tasha's mind whip instead. Damage is: 12 Save is Int 18.

Int Save: 17

The fiery giant of a humanoid's head violent snaps to the response as Robin's spell strikes.

Onyx finds him in an awardard position as he finds himself entangled up in burning webs of Salys as he tries to cut off the friblog. 

Initiative 18 

Salys initiative: 14

Initiative Order

Onyx - 26 - Arrow shots
Resfaen - 19 - Axe attacks
Rogi - 18 - aura of purity
Salys - 14 - Web
Robin - 23 - Cast Mind Whip

Firblog - 4

(Surprise round on the enemy hell i didn't expect the attack) 

Rogi will cast aura of purity.

Resfaen Init: 16

Robin initiative: 23

(Just assume surprise round went as post rather than in order)

As the party assault the fiery continued, Rogi manages to cast his aura but soon after a loud crack of thunder before the ceiling above them shatters as a thunderwave DC 11 sweeps through the room right on top of Bearskr and Salys (assuming he's riding like normal). On fail, Bearkskr and/or Salys will be pushed out of the room. [Spending legendary action]

A large figure drops down following the thunder before landing on the floor. In one hand is a green growing scythe (Re-Favored Warpick) and a metal shield in the other. The figure is a Firbolg with darker than normal skin tone, his brown facial hair giving his head a skull like appearance. An occasional glow emits from him, giving him a green eerie glow to him through his plate armor. No lantern appears on him however. 

"Who shall be the first tribute?" He questions in a loud booming voice.

Turn Order
Onyx - 26 - 5 Fire for burning webs
Robin - 23 - 
Enemies - 20
Resfaen - 19 - 
Rogi - 18 - 
Salys - 14 - 

Assume positions: The enemy dropped in between Onyx/Resfaen with fiery being near the fireplace and Robin/Rogi/Salys near the doorway. 

Forgot Thunderwave Damage: 6

A few questions:

• Onyx took fire damage, i assume the web is burned and he is no longer restrained.
• how big is the room?
• the fireplace had handholds that could be used to climb up, do i see anything up there that would suite as a spot to snipe down into the room?
• fire ghost is still alive?

Answers:

Web burned away completely so not restrained

Room is about is 25ftx25ft 

Peering into the fireplace shows there's another hole farther up Onyx believes leads to the floor above that the figure just came crashing down from/ (Vertical U Turn basically)

Fire ghost is still 'alive' (very durable little thing)

„I always wondered what happens to the owner when he dies…“

Onyx uses his enhanced movement to go to a place in the room where he can freely shoot the firebolg with the green scyth, but still be close to Rasfean to enjoy the paladins aura.

He shoots two divine arrows at the enemy:

• Attack: 25 Damage: 17
• Attack: 25 Damage: 12
• the first attack that hits does an extra 2 damage (same damage as attack, so divine or magical piercing) and he needs to make a DC 16 wisdom save or get disadvantage on all attacks except against me

Wi Save: 7

(Correction: he has no shield but does have plate armor)

Using legendary action #2

Unnaturally focus as the first arrow pierces through his armor but the second shot is defected, his free hand whips from his side as he draws a strange metal object and points it at Onyx, with a familiar bang from countless time Salys has used his firearms echoes as he pulls the trigger aiming at Onyx.

Attack: 8 Damage: 5 Piercing

Onyx and Co. hears a undramatic click before the man lets out a few curses, smacking it against his legs a bit.  [OOC: faceplam]

Resfaen laughs at the creature as she activates her Axe and starts slamming it down upon the creature.

Sun Axe: Attack: 19 Damage: 8

Sun Axe: Attack: 24 Damage: 9

And will dump a couple of divine smites into the attacks.

1st attack: 2 Radiant Damage

2nd Attack Crit: 20 Radiant damage

Turn Order
Onyx - 26 -  - Radiant arrows and Goading attack
Robin - 23 - 
Enemies - 20
Resfaen - 19 - Axe Strikes (I doubt it'll matter but she can change action after enemies go)
Rogi - 18 - Bless
Salys - 14 - Need DC 11 Con save for himself and Bearskr for Thunderwave

[OOC: Sorry thought the enemy went, but I guess that was just the Legendary Action.]

((Dex save vs thunderwave: 8))

On his turn, Rogi will bless Res, Onyx and Cyth. 

Salys con save: 7 
Bearskr con save: 25
+3 from Resfaen's aura if close enough.

Salys will use Flash of Genius to add +5 to his save.

Robin casts Tasha's Mind Whip at 3rd level. She targets both of the enemies...

DC 18 Int save for both for half and not suffering the other affects, or take 11 damage and suffer other affects of the spell.

If the main enemy makes the save, I.E. doesn't use a legendary resistance point, then Robin will force a reroll. Just as well force them to burn legendary resistances if the thing has them.

(Salys, Resfaen is on other end of room so no aura)

Fiery Spirit: 18

Scythe Wielder: 12
Indomitable from Scythe Wielder: 6
Robin's Forced Reroll: 10

The Fiery spirit grips its head as its form flickers out like a extinguished fire, leaving nothing behind. the Scythe wielder seem to delays a bit longer as it head fights back and forth before it seem to stick with a droplet of blood dropping from his nose.

On his turn, he takes a pause in the fight as he cracks open this firearm and seem to work on it for a moment with his free hand but he snap it close, grumbling about moment killer. 

Tinker Tool Check: 25

Next Up: 
Resfaen - Axe Strikes (I doubt it'll matter but she can change action after enemies go)[Legendary Action #1]
Rogi - Bless
Salys - Heat Metal [legendary action]
Turn 3

Onyx - Arrowws Shot Goading attack [Legendary Action]
Robin -