Setting up this part of the adventure.

Strong Start.

The characters come across a nest of skeletal sprites surrounding a desecrated fae gate.

Possible Monsters

Skeletal Sprites

Imagine sprites with once-delicate wings now tattered and spectral. Their bones might be entwined with remnants of their former flesh, and their eyes glowing with an unearthly blue or green light.

Hit Dice: 1d8 (4 HP)
AC: 13
Attack: +0 to hit, 1d8 damage (sword)
Alignment: Neutral
XP: 25
Notes: Dead and Mindless (the sprites are immune to sleep and charm effects)
Spectral Wings These skeletal sprites can glide silently and swiftly, making them elusive targets in battle. Their wing beats create a haunting melody that can momentarily paralyze those who hear it.

Captain of the Dead
This is a mighty warrior in the armies of the dead. It could represent the remains of someone who was a mighty champion in life, or a specially animated officer in an organized army of the dead. It leads not of its own volition, but by the will of its master.

Hit Dice: 3d8 (14 HP)
AC: 15
Attack: +3 to hit, 1d8 damage (sword),
Alignment: Neutral
XP: 90
Notes: Dead and Mindless (the captain is immune to sleep and charm effects)

Encounter at the Fae Gate.

Our party of six and their moose leave behind the woodland and begin their assent of the far mountains towards the monastery

A biting winds howls through the far mountains, each gust carrying a spray of icy needles that stings exposed skin and blurs vision. The snowstorm, relentless in its fury, turns the world into a swirling vortex of white. Every step forward a battle against the elements, the snow crunching underfoot and the cold seeping into their very bones.

With visibility reduced to mere feet, the adventures feel the eerie sensation of being watched. Ghostly silhouettes of leafless trees loom out of the blizzard, their twisted branches reaching out like skeletal hands. The air is thick with an oppressive silence, broken only by the distant, haunting cries of the damned, echoing eerily through the mountains.

As they press on, each moment seems to stretch into an eternity. Fatigue begins to set in, their breaths coming in labored puffs of mist. The ground beneath them becomes uneven, and they stumbled over hidden rocks, their progress slow and treacherous.

Suddenly, through the swirling snow, a dim, flickering light appears in the distance. Drawn to it like moths to a flame, they cautiously approached. The light grows stronger, revealing itself as ghostly blue flames flickering around a twisted, ancient archway. The gate is made of stone, covered in eldritch runes that glowed faintly.

As they draw closer, the realization hitsthem—the gate is not just ancient, it is desecrated. The once-beautiful carvings of fay magic are marred by dark, sinister markings. The air around the gate is thick with a malevolent energy, and the flickering flames cast eerie shadows that dance and writhe.

Then, they saw them—skeletal sprites, their tattered wings fluttering silently in the wind. The sprites move with an unnatural grace, their hollow eye sockets glowing with an eerie blue light. They whisper in forgotten tongues, their voices blending with the wailing winds. Standing at the gate, a large humanoid figure which they recognise as a captain of the dead.

To late to turn and run, the party ready their weapons and prepare to meet their foes.

Combat.

(this was quite a long combat encounter, to give a blow by blow account would be a little tedious to for the reader, therefor I have just summerised it here.)

Culdus, not a natural fighter, readies his faewood staff, hoping he can summon a woodland or mountain creature intime to aid them.
Hew, keen to enter the fray, draws his longsword, He sees standing at the fae gate the captain of the dead, and decides to charge towards it.
Karina, wraps herself in her cloak of shadows, becoming invisible, She draws her short sword and readies herself to attack the undead creatures.
Rhian, believing her enchanted arrows to be little use against undead, draws her sword of flames, and prepares to do battle, a blue flame shoots from the tip of the sword.
Strawberri, knows she has no magic she can weave against the undead, but she knows stones from her sling will shatter their bones. She gets on top of Crea’s moose and loads her sling with stones.
Crea, has the Banish Undead spell and attempts to cast it.

Crea’s Banish Undead spell has mixed results, 6 of the Skeleton Sprites and the Captain of the dead manage to make their save vrs spell rolls, the other six Skeleton Sprites are banished.

Hew reaches the captain of the dead, although he gets one hit on it, causing 6hp damage, the captain proves to powerful for Hew, and caused 8hp damage, dropping Hew down to just 2hp. Hew beats a hasty retreat.

Culdus used his staff to call for aid, a pack of six mountain wolves answer his summons but it will take them (roll 1d8) 5 combat turns to get there. He does however manage to defeat one Skeleton Sprite with his staff, but not before taking 2hp damage himself.

The flame from Rhians sword proves ineffective against the undead. She does take one Sprite down and damages a second but takes 6hp damage herself, which drops her down to just 2hp.

Karina sneaks behind the second Skeleton Sprite attacking Rhian and gets a free hit on it, the creature crumbles.

Strawberri, an ace shot with her sling, takes out another Sprite.

With only two Sprites and the Captain of the Dead still standing, Crea manages to cast a second Banish Undead spell. This time only the Captain of the Dead is banished, but it is enough and the two remaining Skeleton Sprites are quickly overwhelmed by the adventures ending the skirmish.

As the combat draws to a close, the wolves called by Culdus appear. He thanks them for their trouble and sends them on their away.

The Fae gate is open, and they are tempted to go through to see where it may lead them, but with Hew and Rhian both dangerously low on hit points and with the blizzard abating, they decide to press on to the Monastery.

Although their going is difficult, Crea manages to lead them safely and without further incident through the mountain passes. As dusk begins to fall they see the Monastery up ahead. It looks in total darkness, devoid of life and deep snow covers the ground. Crae looks worried and fears they may have arrived back too late.

to be continued.