(Does one in red by stairs also need to save versus well-groomed swordsman's spell?  And second roll for critical damage vs Dain?)

The man in the red robes was just outside the blast radius. He, unfortunately, is fine.
Molo remains on his feet, taking only 4 hp.

Everyone may act.
Dain should roll that DC12 CON save.
Katernin may decide to keep or drop the wind wall.
Molo can get an opportunity attack against the swordsman, but only if he can bypass the windwall.

Molo gives everyone the finger and runs up the steps and out, limping on his club foot

Dain Con save: 24

updated with damage from blast and crossbow critical 

Molo storms out. (Is that a Dash? He can get to the top of the stairs with Katernin on a Dash with his bad foot.)

Everyone else may act!

   Katernin: 18 (concentrating on wind wall)
√ Molo: 13 (scimitarless)
   Dain 8 (maul-less but scimitared)
   Kelnan: 7 (concentrating on cloud)
   Ozymandius (Yellow Robes) 12 (in adjacent room to SE)
   Swordsman with short bow 7
   One crossbowmen (woman with white hair) 7 (in stinking cloud)
   Stringy-haired crossbowman in other room 7 (with Ozymandius)
   Robed figure in red 5

Quote from nschrock >>

Molo gives everyone the finger and runs up the steps and out, limping on his club foot

 Up and out as far as a dash will take him

Katernin, Dain, and Kelnan are up next! (If you act and/or roll outside of this forum, just let me know.)

Dain rushes around to grab his fallen maul and then barrages right through the wind wall once again. OOC: Dash action.  Expecting to take some damage from Wind Wall to maintain his rage, for now.

Strength save: 12

Dain grabs his maul and plows headlong into the debris-filled wind column. (He takes 12÷2 bludgeoning damage and maintains his rage.)

(An incredibly fast sprinter, Dain can grab his maul, plow through the wind wall, and then make his way through his comrades and out into the cold if he chooses to. Or does he prefer to stop next to Fianna's body and protect the others?)

Katernin and Kelnan are up next!

Dain:

Definitely stopping to protect the others. He will be last out. If he has enough movement can he reach that position with 35 ft of move? If so, he will stop and use the Dodge action. But no worries if he needs to Dash to@achieve that.
For reference Dain is now looking Heavily Injured.

With his maul recovered, Dain manages to make his way through the wind to a position in front of Kelnan, next to the fallen Fianna, without breaking into a Dash. He prepares to Dodge any incoming attacks. Katernin and Kelnan are up next!

Kelnan again descends far enough to hit the hooded figure he targeted previously with a Ray of Frost and retreats up the steps with the rest.

Attack: 10 Damage: 8

Placeholder

Katernin steps forward and touches Dain with a healing hand, curing 12 hp of damage. She then retreats back upstairs to where she was. (She still has 20 feet of movement if she needs to go further.)

Kelnan leans around Dain and the bottom of the stairwell to fire another beam of bluish light at the man in red. Unfortunately, he misses, leaving a thin crust of frost upon the far wall.

The arcane swordsman to the west steps forward once more. "Run!" he laughs. "Run! And BEGONE!" He raises his arms as a painfully intense noise erupts from the air in front of you on the starirwell.  Everyone must make a DC 12 CON Save or take 10 thunder damage (half as much damage on a successful save.) The burned doors are blasted from their hinges.

The man in red just laughs.

Everyone may act (once you roll your DC 12 CON Save.)

Initiative:
 Katernin (concentrating on wind wall)
 Molo (scimitarless)
 Dain (mauled and scimitared)
 Kelnan (concentrating on stinking cloud)
 Ozymandius (Yellow Robes) (in adjacent room to SE)
 Swordsman with short bow
 One crossbowmen (woman with white hair) (in stinking cloud)
 Stringy-haired crossbowman in other room (with Ozymandius)
 Robed figure in red

Molo con save 8 

Quote from nschrock >>

Molo con save 8 

 Molo is down again.

Molo collapses, unconscious, from the sonic blast. (Roll your first death save when you're ready...)

Katernin, Dain, and Kelnan must make a DC 12 CON Save or take 10 thunder damage (half on a successful save.)
Then they may act, in any order.

The three standing party members remain crowded on the burned basement steps between the unconscious body of Molo and the dead body of Fianna. The burned, blasted doors have fallen from their hinges. Katernin's arcane wind wall continues to roar, keeping most of Kelnan's foul-smelling cloud at bay. The priest's wall of flitting demons can still be seen guarding the southeast door, together with a choking guard: a badly-injured white-haired old woman wielding a crossbow.

Two other combatants remain in the room - a smirking, red-robed man, and a well-dressed swordsman, both of whom have exhibited potent arcane abilities.
The room is littered with corpses and debris.

Katernin, Dain, and Kelnan must make a DC 12 CON Save or take 10 thunder damage (half on a successful save) from the swordsman's last spell.
Molo must make a death saving throw.
Katernin, Dain, and Kelnan may act.

• Initiative:
  Katernin (concentrating on wind wall)
  Molo (unconscious and scimitarless)
  Dain (mauled and scimitared)
  Kelnan (concentrating on stinking cloud)
  Ozymandius (Yellow Robes) (in adjacent room to SE, protected by spirits)
  Swordsman with short bow
  One crossbowmen (woman with white hair) (in stinking cloud)
  Stringy-haired crossbowman in other room (with Ozymandius)
  Robed figure in red
  
  

(I rolled an 11 on the CON save in DDB/Avrae)

Kelnan's Arcane Ward absorbs the shockwave, nearly blasting it clear away. He fishes a healing potion from his bag, administers it to the unconcious Molo (heal 4 HP), and evacuates the room, waving his rod threateningly on the way out.

Dain grabs the prone but now conscious Molo and throws him over a shoulder. Letting Katernin take the lead he exits following Kelnan. 

Kelnan and Dain exit into the gray, frozen moors of this desolate island, carrying Molo. A cold wind gusts. It is deeply overcast. It's about midday.

Katernin brings up the rear. Fianna's lifeless body remains on the stairwell.

Kelnan's stinking cloud (90' range, 1-minute duration) will soon expire, as will Katernin's wind wall (120' range, 1-minute duration). They may also drop it at will.

There are no immediate signs of pursuit. Initiative is paused.