Lia con save: 20

Rhok con save:   4

OOC: oops, down he goes

Xarroth tries to still the shakes that have worked their into his very core...

Wisdom Saving Throw: 16

The dragonborn feels his mind embrace the memory of the warm sunlight the day he received his vestments; the day the Platinum Dragon's blessed his charge to help put the world to right. With that, he turns to helps his comrades rid this thing that clearly no longer belongs...

Rhok falls to the floor unconscious. As the ranger drops you see the banshee gliding through a door in the hallway, disappearing from sight.

Lothlién goes next.

OOC: the banshee is moving out of order because I forgot about it on her turn. The combat initiative is still going even if she is out of sight.

Lothlién's CON save: 24

Lothlién resists most of the effect of the wail, but his mind is still deeply disturbed. The vision of the banshee traversing a door is an unerving mix of relief and anxiety - it's no longer here, but where is it now? when is it coming back?

A couple of seconds go by before he comes to himself again, and runs to assist Rhok.

Stabilize check: 13

The ranger's breathing returns to a normal rhythm after Lothlién tends to him. He is out of danger and will be back to consciousness in 2 hours.

Lia goes next.

OOC: the banshee took the middle of the three doors going south in the hallway.

Lia casts misty step to reach the door. Once there she tosses it open (free action I hope) and sends a mental attack at the spirit, if she can see it.

mind sliver

DC 14 Int save. Damage is 4

Int saving throw: 17

Lia opens a door furnished with elegant furniture. The banshee is floating over the center of the room. She resists the mental attack and glides towards Lia, extending an arm to touch her.
Attack: 8 Damage: 18

Initiative order:
23 Lia
20 Banshee (22, in melee with Lia)
19 Rhok (unconscious, stable)
14 Xarroth
11 Lothlién

Rhok is stable but unconscious, Xarroth goes next.

Seeing that his friend is not in grave danger anymore, Lothlién follows Lia. If the banshee is in his sight, he'll try a different spell this time:

Magic missiles: 3; 4; 5

Xarroth, now warmed by courage, will re-enter the room with the banshee - looking to make up for lost time.

If he can see banshee with the door now open, and its within the spell's range he will cast Scorching Ray.

Scorching Ray (2nd Level)
Ray #1 - Ranged Spell Attack: 19 Damage: 6 (fire)
Ray #2 - Ranged Spell Attack: 23 Damage: 4 (fire)
Ray #3 - Ranged Spell Attack: 18 Damage: 3 (fire)

If he needs to get closer, he'll take the Dash action to get closer.

Xarroth's Scorching Ray hits the banshee multiple times, closely followed by Lothlién's magic missiles. The undead is looking somewhat damaged at this point.

Initiative order:
23 Lia
20 Banshee (40, in melee with Lia)
19 Rhok (unconscious, stable)
14 Xarroth
11 Lothlién

Lia goes next.

Lia casts Mind Sliver again...
DC 14 int save or take 8 damage.

OOC: Did the magic missiles hit her hard, or did they look ineffective as the scorching ray?

Int save: 14

The banshee barely resists the mental attack and retaliates with a touch attack against Lia.
Attack: 8 Damage: 10

Initiative order:
23 Lia
20 Banshee (40, in melee with Lia)
19 Rhok (unconscious, stable)
14 Xarroth
11 Lothlién

Xarroth goes next.

OOC: the magic missiles did normal damage.

Xarroth sends a searing drop of flame towards the banshee!

Fire Bolt- Ranged Spell Attack: 14 Damage: 20 (fire)

Fire burns around the banshee, her face contorts in rage at the damage.

Initiative order:
23 Lia
20 Banshee (50, in melee with Lia)
19 Rhok (unconscious, stable)
14 Xarroth
11 Lothlién

Lothlién goes next.

Noticing that the magic missiles worked, Lothlién sends another volley at the enemy

Magic missiles: 2, 5, 4

OOC: damn those rolls!
I'll use my Empowered spell. Since it's all 1spell I think I can reroll all of those dice, but if that's wrong just take the first one!

2, 1, 4

Lothlién's magic missiles hit the banshee, making the undead fade into thin air in the middle of the room. Lia feels the air move her hair as it rushes to fill the void left by the undead.

OOC: there is no consensus on how to roll damage for magic missile. Some people roll once and apply that roll to every dart. Some people prefer to roll for each dart. I'm ok with either of them. In this case, you can reroll up to 4 (your charisma modifier) damage dice per spell, so rerolling all of them looks fine to me.

"Be gone, dreadful spirit!" Lothlién speaks as the fear starts to fade away with the Banshee.
"I think I need some rest, and Rhok surely does. Do you guys think we can take a break in this room? Maybe we can barricade the door and make it a bit safer for a while" he sugests a few seconds later.

Rhok emits slight moans while unconscious