Groom Minion: Lethe

A ghost without definition or personality, the lethe is a pitch-black silhouette save for reflective, lifeless eyes. It is all that remains of a suicidal nepenthe cultist intent on bringing the rest of reality down with it so it might please the stoic Groom. Accompanying the lemure is a moist, grey fog that quickly gets under the skin and dulls one's wits.

Curse of the Lethe. A lethe is driven by a single task; wiping all sense of being from the world. Through its actions the apparition hopes to bring about a state of nothingness for everyone and everything. This intense focus grants the lethe the ability to wipe away the memories of its victims in a deluge of necromantic energy. Most heroes shake off this temporary fugue, but should they succumb the victims find their minds permanently impaired until treated with magic.

Lethe

medium undead, chaotic evil

Armor Class 13

Hit Points 49 (11d8)

Speed 0ft

Flight 40ft (hover)

Str 5 Dex 16 Con 11 Int 4 Wis 14 Cha 17

Damage Immunities cold, necrotic, poison

Damage Resistances acid, fire, lightning, thunder; bludgeoning, piercing, and slashing from nonmagical attacks not made with non-magical weapons

Condition Immunities charmed, exhaustion, frightened, grappled, paralyzed, petrified, poisoned, prone, restrained

Senses darkvision 60ft, passive Perception 10.

Languages -

Challenge 5 (1,800 XP)

Ethereal Sight:

The lethe can see 60 ft. into the Ethereal Plane when it is on the Material Plane, and vice versa.

Incorporeal Movement:

The lethe can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Numbing Aura:

The lethe constantly emits an oppressive aura in a 15-foot radius that dulls the mind and numbs the soul. When a creature enters the area for the first time or starts its turn there it must make a Wisdom saving throw DC 14. On a failed save a creature forgets what it intended to do and its turn immediately ends. If the creature was concentrating on any spells they immediately end as well.

Actions

Oblivion's Caress:

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 14 (4d6+3) necrotic damage.

Etherealness:

The lethe enters the Ethereal Plane from the Material Plane, or vice versa. It is visible on the Material Plane while it is in the Border Ethereal, and vice versa, yet it can't affect or be affected by anything on the other plane.

Flood of Forgetfulness (Recharge 6):

The lethe unleashes a wave of memory-devouring magic in a 20ft cone from its eyes. Creatures within this area of effect must succeed on a DC 14 Wisdom saving throw or have their thoughts become jumbled for the next minute and take 21 (6d6) psychic damage.

An affected target can't take Reactions and must roll a d8 at the start of each of its turns to determine its behavior for the turn.

1: The creature uses all its Movement to move in a random direction. To determine the direction, roll a d8 and assign a direction to each die face. The creature doesn't take an action this turn.

2-4: The creature doesn't move or take Actions this turn.

5-6: The creature uses its action to make a melee Attack against a randomly determined creature within its reach. If there is no creature within its reach, the creature does nothing this turn.

7-8: The creature can act and move normally.

At the end of each of its turns, an affected target can make a Wisdom saving throw DC 14. If it succeeds, their mind clears and the effect ends for this target. If it fails, the effect continues and the creature takes an additional 10 (3d6) psychic damage.

If a creature is reduced to 0 hit points by the Flood of Forgetfulness and survive they suffer from the Lethe Curse. (See Below)

Lethe Curse. While the victim has recovered after drowning in a lethe's flood of forgetfulness, it finds its mind fuzzy and wits dulled. The creature has disadvantage on Initiative and Intelligence save and skill checks. The Lethe Curse can be removed via the Remove Curse spell and effects like it.