Nalfeshnee

If the nalfeshnee 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 nalfeshnee has Advantage on saving throws against spells and other magical effects.

The nalfeshnee makes three Rend attacks.

Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 20 (2d10+5) slashing damage plus 11 (2d10) force damage.

The nalfeshnee teleports up to 120 feet to an unoccupied space it can see.

The nalfeshnee emits a magical aura of horror. Each creature of its choice in a 15-foot Emanation originating from the nalfeshnee must make a DC 15 Wisdom saving throw. On a failed save, the target takes 28 (8d6) psychic damage and has the Frightened condition for 1 minute, until it takes damage, or until it ends its turn with the nalfeshnee out of line of sight. On a successful save, the target is immune to this nalfeshnee's Horror Nimbus for 24 hours.

Trigger: Another creature the nalfeshnee can see ends its move within 120 feet of the nalfeshnee. Response: The nalfeshnee uses Teleport, but its destination space must be within 10 feet of the triggering creature.