Haunted Woods

Based loosely on this GW2 event chain.
Strange lights have been seen in the woods near Rox. Those who have gotten close report spirits and a sense of foreboding overcoming them until they fled.

Upon approaching the place at night, they indeed see Spirits wandering the woods. They appear passive, if interacted with, they breathe a warning to turn back.

Deeper in the woods they find a woman dressed in dark wrappings, her eyes and hair covered by the cloth, alongside a small shrine to Grenth and a brazier, with a crystal heart floating above the blue flames. The woman sees the party, and immediately prepares to defend herself. She compels 3 of the spirits to defend her. Note that for balance, if the party is low-leveled, spirits only do 1d6, instead of 3d6 with their attacks.

The Ritualist

Stat	Score	Abilities	Notes
HP	90
AC	15
STR DEX CON INT WIS CHA	-1 12 0 3 1 1	Compel Spirits	The ritualist commands 2 nearby spirits to become hostile, joining the fight.
		Legendary Action: Spirit to Flesh	The ritualist destroyes one of the spirits, healing for twice the spirit's remaining health
		Reaction: spirit shield	She compels a spirit to take an attack for her.
		Once the crystal is destroyed, she can no longer compel the spirits, but any that she has under her control remain so.

The Crystal

Stat	Score	Notes
AC	10	The crystal cannot be hurt by magical damage, but is weak to Bludgeoning. Any damage dealt to it is reduced by 5.
HP	5
Damage Threshold	5

Aftermath:

Once the Ritualist is dead, the spirits are freed, passing into the afterlife. The party gains a level from the encounter. the Crystal Heart, or what's left of it, has no magic, but remains a valuable gem nonetheless. The shards can be sold for a sum of 300gp, or if repaired with mending over the course of a long rest, it becomes worth 1000gp to a discerning jeweler. On her body is found an emerald inlaid amulet