Nalfeshnee

If the monster dies outside the Abyss, its body dissolves into ichor, and it gains a new body instantly, reviving with all its Hit Points somewhere in the Abyss.

The monster has Advantage on saving throws against spells and other magical effects.

The monster makes three attacks.

The monster teleports up to feet to an unoccupied space it can see.

. .

Wisdom Saving Throw: DC , each in a -foot Emanation originating from the monster.
Failure: damage, and the target has the Frightened condition for , until it takes damage, or until it ends its turn with the monster out of line of sight.
Success: The target is immune to this monster's Horror Nimbus for 24 hours.

Trigger: Another creature the monster can see ends its move within feet of the monster. Response: The monster uses Teleport, but its destination space must be .