Where the Deep's dream tore — some say at the Threshold of Sighs, some say wherever a Heartweave pilgrim died still dreaming — a wound in sleep learned to walk. Oneiroth is a Huge drift of borrowed faces and half-remembered rooms, and it does not want to kill you so much as to remember you, which is worse, because what it remembers, you forget.
- CR
- 17 (XP 18,000)
- Type
- Aberration
- AC
- 19
- HP
- 322
- Habitat
- Mycelial Deep
Huge Aberration (Dream), Chaotic Neutral
AC 19 Initiative +11 (21)
HP 322 (28d12 + 140)
Speed 40 ft., fly 40 ft. (hover)
Skills Insight +11, Perception +11
Resistances Bludgeoning, Piercing, Slashing
Immunities Psychic; Charmed, Frightened, Grappled, Prone, Restrained
Senses Truesight 120 ft.; Passive Perception 21
Languages Understands all languages; telepathy 120 ft.
CR 17 (XP 18,000; PB +6)
Traits
Legendary Resistance (3/Day, or 4/Day in Lair). If Oneiroth fails a saving throw, it can choose to succeed instead.
Dream Logic. Oneiroth has Advantage on saving throws against spells and other magical effects, and its own effects can't be dispelled by magic below 6th level.
Unreal Form. Oneiroth doesn't occupy a fixed shape. It can move through creatures and objects as if they were Difficult Terrain; it takes 5 (1d10) Force damage if it ends its turn inside an object.
Remembering Gaze. Emanation. A creature that starts its turn in a 30-foot Emanation around Oneiroth and can see it makes a Wisdom Saving Throw: DC 19. Failure: 16 (3d10) Psychic damage, and the target has Disadvantage on the next attack roll or ability check it makes before the end of its next turn as a memory slips loose.
Actions
Multiattack. Oneiroth makes three Grasp of Faces attacks and uses Unmaking Whisper if available.
Grasp of Faces. Melee Attack Roll: +11, reach 10 ft. Hit: 18 (3d8 + 5) Psychic damage, and the target makes a DC 19 Wisdom saving throw or has the Frightened condition until the end of its next turn.
Unmaking Whisper. Charisma Saving Throw: DC 19, one creature Oneiroth can see within 60 feet. Failure: 36 (8d8) Psychic damage, and the target's Hit Point maximum decreases by an amount equal to the damage taken until it finishes a Long Rest. If this reduces the target's Hit Point maximum to 0, the target is pulled bodily into the dream and has the Petrified condition until Oneiroth is slain (it stops aging and needs no air). Success: Half damage, and no reduction.
Nightmare Made Real (Recharge 5–6). Wisdom Saving Throw: DC 19, each creature in a 30-foot Emanation. Failure: 45 (10d8) Psychic damage, and the target has the Frightened condition until the end of its next turn. Success: Half damage only.
Legendary Actions
Legendary Action Uses. 3 (4 when in its lair). Immediately after another creature's turn, Oneiroth can expend a use to take one of the following actions. It regains all expended uses at the start of each of its turns.
Drifting Step. Oneiroth teleports up to 40 feet to an unoccupied space it can see, dissolving and reforming from a dreamed image.
Reweave. Oneiroth makes one Grasp of Faces attack.
Borrowed Face (Costs 2 Actions). Wisdom Saving Throw: DC 19, one creature Oneiroth can see within 60 feet. Failure: The target has the Charmed condition until the end of its next turn, seeing Oneiroth as someone it loves.