Phosma and Blue Breath Devils

Hollow Earth Theory

If you go down far enough below Centerra, you'll eventually end up in the Interior.  The planet has a central sun, which is dim and blue and cold.  It wavers in the sky, like rimless blurs of dye drifting through still water.  This star is called Phosma.

Phosma

But the interior star is only one manifestation of Phosma, the gaseous superconsciousness at the center of the planet.  It's like an ocean of incoherent thought, for the most part, but enough parts of the fragmented supersentience can cooperate to control the planet, the form of subsonic vibrations (slow) and tectonic movement (very slow).

Phosma can also control it's orbit.  It is fighting a war with its neighboring planet, Nastromar.  Also known as the Black Planet, Nastromar has been pursuing the much smaller Phosma for the last 6 billion years, seeking to destroy it.  (Nastromar has a very erratic orbit.)  Phosma has been retaliating by throwing moons at its nemesis.

At the Eye of the World, the Observatory Umbilicus (nestled in the magma like a pearl) records these subsonic vibrations of the planet.  They have built a system of magnetic superbells that they use to communicate with the planet.  The planet speaks Elvish.  It can pronounce about one word per day.

For the last six months, the planet has been repeating the same phrase, over and over again.

"I am so sorry."

Which is frustrating for those at the Observatory Umbilicus, because many of them rely on Phosma for news for Nastromar and meteor showers, and also because many of them want to know what the planet is sorry for.

Blue Breath Devils

When the gaseous mass of Phosma is disturbed, parts of it sometimes break away.  The wings of an anti-dragon plumbing the Plutonian sky, for example, might create an eddy of blue gas that whorls away.

This puff of blue gas is sentient.  Most of them immediately rejoin Phosma, but some wander away, confused and alone, where they eventually develop their own names, personalities, and agendas.

In Centerra, they are known as blue breath devils.  They float around (a la gaseous form) but are incapable of doing much, except (a) suck the air out of your lungs or (b) enter your lungs and control your brain.

Blue Breath Devils usually hate each other.  Powerful devils can absorb smaller ones (Bigger HD absorbs the smaller HD one), but they can also remix themselves: trading memories and skills.

Not having bodies, they usually study magic.  You'll hardly ever find one 'naked'--they're usually found possessing a choice humanoid--either a burly barbarian or a local ruler.

They are known to the Church (who categorize them among the Devils).

In the frozen south, Blue Breath Devils secretly rule most of the viking clans and fortified city-states.  Urbanized devils sometimes work together toward broader agendas.

Stats

HD 4 or higher
AC 8 (+ gaseous form effects)
Mv fly at walking speed
*Cast spells as a wizard of their HD, in any form

**Breathing is not possible while within their cloud (~10' for a 4 HD breath devil) and creatures that enter the cloud must make a Con check to avoid inhaling tiny bits.  Failure means that they are immobilized for 1d6 rounds as devil-magic lifts them a couple of feet off the ground, and they take 1d6 damage for each round they remain in the cloud as tiny claws rake their lungs to shreds.

***They can attempt to possess a creature by forcing themselves into its lungs.  This requires the creature to fail a Constitution check.  Once inside the lungs, the devil can take over the brain by forcing a Save on their turn, while the PC can cough them out by making a Con check with a -4 penalty.  While possessing a creature, they have a breath attack (usable 1/hour, 15' cone) that causes the targets to be lost while they relive their memories.  To break free from this effect, the PC must describe one of their memories and fail an intelligence check (dumber PCs break free from their memories easier).  They can attempt this once per turn.  Possessed creatures' eyes turn blue.  If a possessed creature is forced totally underwater, they get a new save each turn to expel the blue breath devil.