It's 3am, so I'll be short, but I can always provide more information if you want.
Psionics are very rare in my game. They are a form of soul-based magic, imprinted on the mind. The first psionic PC I had in my campaign was a psion/monk who used psychometabolic powers, drawing on the essence of the souls of other creatures and infusing part of their aspect into himself to gain their abilities.
Then came Trilla, a young gold dragon who was exposed to demonic energies from an abyssal portal. Later, in an attempt to purify her, she was exposed to the holy energies of a heavenly portal, and the combination of devilish spirits trying to possess her and angelic spirits trying to protect her created in her the unique ability to manifest her thoughts into new entities. At first she had no control over her powers, so every night when she dreamed, her dreams would become real.
These early dream incarnations were weak, barely formed, hardly even sentient. Trilla was worried by them, as was her mother, Psiana, but Trilla eventually learned to trap the incarnations by sculpting figures of faces with closed eyes. If a dream incarnation, in its weak, intangible state, entered one of these statues, it would not see its way out, and would be trapped.
Unfortunately, Trilla's powers also became entangled with a powerful artifact, the Torch of the Burning Sky. The Torch was actually the thighbone of the demon who infused Trilla, and it was used as a club to slay the angel that tried to heal her. At this time, the Torch absorbed a bit of Trilla's draconic powers, and gained strange access to fire and teleportation powers. The bearer of this Torch led armies to conquer the world, but because one of the warlord's allies, an Elf named Shaaladel, was friends to the Dragons, Trilla and Psiana were safe. Safe, that is, until the warlord's ally tried to recreate the event that formed the Torch, torturing Trilla and driving her to create her first true nightmare, Agony.
Shaaladel's new artifact was destroyed by Psiana, but Shaaladel fled and had Psiana murdered, then ordered the capture of Trilla so he could try again. Trilla's first full sentient incarnation, Life, helped her escape and survive, and Trilla was smuggled deep underground by Elves that were fleeing the power of the new Ragesian Sun Empire. After this point, lore about Trilla becomes very vague on the surface, though more is known by those who live underground.
Trapped deep underground, alone after her mother's death, Trilla's nightmares intensified, and she created ever stranger and more deadly incarnations. Afraid of hurting those who had tried to protect her, Trilla fled the care of the Elves and found a deep, hidden place to make her new home, hoping she could find a way to stop the dreams from coming. She made some progress, keeping herself awake and concentrating on trapping any new incarnation before it could come to full strength.
But Life resented this. To quell the creation of new incarnations was the opposite of this entity's complete existence. One night, while Trilla dreamed, Life whispered the greatest terrors it could conjure to the sleeping Dragon, terrors driven from fear of loss of control, from guilt and grief. Trilla twisted in her dreams, screaming in fear, and thus was born Horror. Life stole away with the newborn incarnation, to nurture it and teach it how to manipulate their mother's sleep and dreams, and soon, Trilla found herself weaker and weaker in the face of these growing nightmares.
Years passed, Trilla trying to resist, trying to conjure incarnations that would aid her. Indomitability, Balance, Peace, Joy. Nearly all of these were subverted by Life, Trilla's dreams overpowering her, finally gaining enough strength to place her in a state of unending sleep. Now she slumbers eternal, her mind filled with whatever horrors her children wish to create.
The incarnations tried several times to reach the surface, but Trilla had done well to seal the escapes. Only a few have reached the surface, some trying to explore, others trying to gain power for their eventual release. A few are still yet loyal to Trilla, however, and they have bonded with humans on the surface, hoping to heal the pain of the Mother of Dreams.
Alright, so it's not really short, but that's the backstory. As to stats, they're all over the place. The incarnations count as, basically, ghosts, or other incorporeal undead, since they are simply spirits without bodies. However, they can manifest into physical bodies somehow related to their nature, and they can also possess a creature or object and infuse it with their essence. The magic of a rare group of subterranean fey lets a singer trap an incarnation into a physical form, and only in such a form can the incarnations be truly slain.
A few examples:
The strongest incarnations the PCs have encountered include Time, Indomitability, and Agony. Time never became tangible, but inhabited a grand cavern that contained the secret of immortality. Indomitability was one of the first dreams to reach the surface, and it arrived in the midst of a raging forest fire. Gallingly, it was trapped in physical form by the fey song, forced into the body of a giant flaming elk, but Indomitability's power was so great that the forest would never fall, so its flamed burned for over sixty years. Agony was trapped in a dungeon-prison by an evil wizard, and it would fill all the inmates with the most intense pain every few hours. They also just met Desire, but most of its powers are drawn from the psychic energy of others.
Some weaker incarnations they've met have included Deception (who has a +60 Bluff check, but little else), Impersonation (it copied two PCs), Balance (an ally of the party, sort-of), Aggression (took the form of dead warriors that would keep fighting), The World Falling Upon Itself, and a strange entity called the Wanderer, which collects dreams from the surface to use as inspiration for new dreams.
Finally, one PC was actually the incarnation of Justice, bonded into a human body, and they're good friends with a young girl who is bonded with Foresight.
In their incorporeal forms, they have lots of strange (often ad hoc) powers and abilities, but they are not able to harm people directly. But Deception could trick people into doing dangerous things, and Desire has been doing a good job tempting one of the PCs into betraying the others. When they assume physical forms of their own free wills, they are still only semi-tangible, but their powers have stronger and more direct effects. Finally, if you force them into a solid form (requires a bardic music performance, though I'd let someone research a spell if they took the time), their powers are very strong.
Indomitability, for one, was a 20 hit-die critter with a 120 Constitution. Deception was actually rather weak physically. Agony rebounded all damage dealt to it back on the attacker, in addition to recall pain, recall agony, and recall death psionic powers.
If you defeat an incarnation, you gain some aspect of its power, or you become resistant to its power. If you kill an incarnation, you gain a strong part of its power, though sometimes this power can overwhelm. The party was very nervous about fighting Agony, for instance, fearing they'd become eternally tormented with pain.
And this whole thing was inspired by a handful of Magic cards that came out in the Judgment expansion.
