space ghost(s)

In Dawn of the Overmind the PCs travel from Earth to Penumbra in a spelljammer/spaceship. On the way they have two set encounters – one in the phlogiston which I had the ship describe as being a “short cut through space” and the players immediately assumed it was a wormhole.  I thought that was a nice compromise between the science-fantasy of my setting and the original spelljammer setting.  In the phlogiston are ephemerals – spirits that died in the phlogiston and, due to not having any access to the astral plane, could not enter the afterlife.

These spirits do their best to hijack ships and then leave the phlogiston so they can head to their afterlife. I made them invisible and rolled the saving throws for the PCs and then handed the ones that failed the save a note that says “you lost 4 intelligence points”.  The PCs panicked and then they failed their save again and lost another 1d4 intelligence points.

I ended up putting them out of their misery and when they were asking Moya if anything had boarded the ship I described how her speech was garbled.  They immediately ran to the shipmind that is Moya and discovered the ephermeals trying to take over.

The PCs made short work of the ephemerals but the point wasn’t for them to be a tough combat encounter but something weird and dangerous in a different way.


Medium undead, unaligned
Armor Class14 natural armor
Hit Points110 (20d8 + 20)
Speed0 ft., fly 30 ft. (hover)

10 (+0)

10 (+0)

12 (+1)

18 (+4)

20 (+5)

17 (+3)

Saving ThrowsInt +7, Wis +8
Skills Insight+8, Perception+8
Damage Resistances acid, cold, lightning, thunder; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities cold, necrotic, poison
Condition Immunities charmed, exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained
Senses darkvision60 ft., passive Perception 18
Languages Common
Challenge 8 (3,900 XP)

Void Regeneration. The ephemeral regains 1 hit point at the start of its turn while in contact with the phlogiston.

Rejuvenation. A destroyed ephemeral reappears in a random location in the phlogiston after 24 hours.

Invisibility. The ephemeral is invisible.

Hijackers. The ephemeral has a trait based on the number of ephemerals within 30 feet of each other, as shown below:

  1. Enfeebling Ray. The ephemeral’s Innate Spellcasting trait includes ray of enfeeblement, which he can cast at will.
  2. Undead Fortitude. If damage reduces the ephemeral to 0 hit points, he must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, it drops to 1 hit point instead.
  3. Unnatural Vigor. When the ephemeral regains hit points, he has advantage on attack rolls he makes on his next turn.
  4. The ephemeral’s Innate Spellcasting trait includesmisty step, which it can cast at will.
  5. Lingering Spite. When this ephemeral is reduced to 0 hit points, its incorporeal form explodes in a burst of necrotic energy. Each creature within 5 feet of it must make a DC 16 Constitution saving throw, taking 14 (4d6) necrotic damage on a failed save, or half as much damage on a successful one.

Ethereal Sight. The ephemeral can see 60 feet into the Ethereal Plane when it is on the Material Plane, and vice versa.

Incorporeal Movement.The ephemeral 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.

Innate Spellcasting. The ephemeral’s innate spellcasting ability is Wisdom (spell save DC 16, +8 to hit with spell attacks). It can innately cast the following spells, requiring no components:

Legendary Resistance (1/Day).If the ephemeral fails a saving throw, it can choose to succeed instead.

Life Drain. Melee Weapon Attack:+8 to hit, reach 5 ft., one creature.
Hit: 18 (4d8) necrotic damage, and the ephemeral regains hit points equal to half the amount of damage the target takes. The target must succeed on a DC 16 Constitution saving throw or its hit point maximum is reduced by an amount equal to the damage taken. The target dies if its hit point maximum is reduced to 0. This reduction to the target’s hit points maximum lasts until the target finishes a long rest. This attack also drains 1d4 points of Intelligence. If the target’s intelligence is reduced to 0 the ephemeral may use Possession as a bonus action or reaction.

Boarding Action. The ephemeral summons all other ephemerals on the spelljammer they have infiltrated. At the start of the ephemeral’s next turn, the other ephemerals appear in unoccupied spaces within 30 feet of the summoner. The ephemeral each roll initiative when they appear.

Possession. One humanoid that the ephemeral can see within 5 feet of it must succeed on a DC 13 Charisma saving throw or be possessed by the ephemeral; the ghost then disappears, and the target isincapacitatedand loses control of its body. The ghost now controls the body but doesn’t deprive the target of awareness. The ephemeral can’t be targeted by any attack, spell, or other effect, except ones that turn undead, and it retains its alignment, Intelligence, Wisdom, Charisma, and immunity to being charmedand frightened. It otherwise uses the possessed target’s statistics, but doesn’t gain access to the target’s knowledge, class features, or proficiencies.

The possession lasts until the body drops to 0 hit points, the ephemeral ends it as a bonus action, or the ghost is turned or forced out by an effect like the dispel evil and goodspell. When the possession ends, the ephemeral reappears in an unoccupied space within 5 feet of the body. The target is immune to this ghost’s Possession for 24 hours after succeeding on the saving throw or after the possession ends.

If five ephemerals are​ all within 30 feet of each other, they can collectively take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature’s turn. Ephemerals​s regain spent legendary actions at the start of the turn of the ghost with the highest initiative.

  • Forced Obedience. A target that all of the ephemeral can see must succeed on a DC 16 Wisdom saving throw or spend the next 1 minute trying to take over the ship and return it to the nearest crystal sphere. The target may repeat the saving throw at the end of its turn.

Ephemerals arethe spirits of those who’ve died in the phlogiston far from crystal sphere to find their appropriate afterlife. Ephemerals appear as dusty gray humanoids who, having neither an Astral connection to the Outer Planes nor an Ethereal connection to the Negative Energy Plane, are infused with and animated by the essence of the phlogiston itself. Attracted by the beacon of the psionic nautiloid, 1d8 of these poor remnants manage to “hop aboard”, phasing their noncorporeal bodies easily into the nautiloid’s interior. Once inside, they immediately move to poses the bodies of the nearest intelligent beings by draining Intelligence. Note that the shipmind qualifies as an intelligent being in this case, and the characters should protect the heart of their craft! In fact, it takes 4 rounds for an ephemeral to possess the shipmind (and therefore the ship).

An ephemeral with a new living host immediately tries to return to any nearby crystal sphere. This may involve slaying anyone who attempt to stop it, including former allies.

The ephemeral usesthe physical abilities of the body it takes over but not any magic, psionic, or special abilities. For instance, an ephemeral could take over a mind flayer, but could not use its mindblast or other psionic abilities. When the host enters a crystal sphere, the ephemeral transforms into a formless spirit, immediately traveling to the OuterPlanes to meet whatever fate awaits it there. The host body, left as a mindless shell in the wake of the creature’s possession, can regain its full Intelligence through the use of a wishspell; otherwise, Intelligence returns at a rate of 1d2 points per day