An alien race far from Earth lived on a mystic planet. At one level, the Fearful consist of a non-sentient virus that infects whatever organic life it touches. The mystic planet where the Fearful first evolved was quite different from Earth. The life forms there fed on mystic energy, which was plentiful. The Fearful, once infecting an entire ecosystem, acquire sentience, with each ecosystem corresponding to one individual. To communicate, they swap pieces of their ecosystems with each other.
The Fearfuls’ original world was mystic for long enough that the planet awakened. None of the creatures there, however, were aware that it had done so. Awakened worlds can sense the Destroyer further in advance than smaller life forms can (those on the scale of humans or even the Fearful). Because of this, the Fearful had some warning when the Destroyer appeared to eliminate their world (the original world’s consciousness amplified the oncoming waves from the Destroyer). Overcome by the dread and loathing, even at a cellular level, they sent off "spores" (e.g., chunks of rock with a large quantity of the virus) into space, hoping they would find other worlds with organic life on which to grow. Unfortunately, this system meant that any new worlds thus colonized with the virus would be unaware of each other.
At least one world was successfully colonized in this fashion: Earth. The Fearful settled in there nearly five millions years ago, quickly taking over some ecosystems. New consciousnesses were born.
Instinctively, they "knew" mystic energy was evil. It had to be purged, or barring that, escaped. A universal religion was created around doing this.
To purge Earth, they began sampling the DNA of humanoids (elves, dwarves and gnomes) to create creatures less able to channel mystic energy (humans). They did not necessarily manipulate the DNA consciously, but at a viral level they were capable of doing it. Humans were constructed to be as "viral" as possible, capable of interbreeding with all the dominant species, but completely devoid of the ability to channel mystic energy. The trait was embedded in them so strongly that anyone descended from humans would be completely unable to utilize magic. In addition, the humans were programmed to be aggressive, curious, jealous and shorter-lived than the other races.
They also worked on a method of escaping the planet should the Peacemaker (their concept of the Destroyer) return. In 6000 BC, the Fearful somehow sensed Emmanuel’s approach when even Gaia paid him no mind – but they jumped to the conclusion that he must be Peacemaker come again. The Fearful panicked and deployed their escape plan, adapted themselves to travel interstellarly through highly efficient biological means, and transplanted themselves (i.e., the infected ecosystems) onto Mars.
From there, they continued their efforts to flee the solar system, to escape the tainted planet. Further and further from Sol they fled, living up to their name. Their current homeworld is approximately fifteen light years from Earth. The Fearful’s religion states that they are running from the tainted planet, and must keep moving from world to world to get as far away from it as possible, in order to achieve salvation.
The Fearful were fairly far along – but not finished – in the evolutionary process of humans when Emmanuel arrived. Hence, the reason that about one in a thousand humans is capable of channeling mystic energy is that humans were not fully evolved according to the Fearful’s wishes before the aliens fled the planet.
The current Fearful ecosystems have evolved greatly since they left Earth. Many of the creatures are still "Earth-like" (i.e., observably evolved from Earth species – not totally alien in origin), but they are now quite distinct from modern-day Earth species. Certainly, the ability of the entire ecosystem (i.e., jungle-like structure) to traverse the stars at speeds upwards of 1/500th the speed of light is astounding to behold.
Using the Fearful in the campaign
This race provides many opportunities for plot threads and mindfucks.
First, the PCs will arrive on a world with an Earth-like ecosystem – probably some kind of strange, dense jungle, with some creatures oddly similar to Earth animals. The ecosystem itself will seem alive, in that the jungle itself will react in a united fashion. They might seem to hate the humans and try to destroy them – as though all the animals and plants are working together to thwart them. Perhaps at first it will be more of a wary curiosity. How things proceed from there depends on how the PCs act.
Once the PCs learn that indeed the jungle itself is alive, and sentient, perhaps they can find a way to communicate with it. Paul’s idea that the virus infects the humans might work – then the fact that they possess sentience might give them the ability to be somehow aware of the greater consciousness of the ecosystem (i.e., hearing a Fearful individual’s thoughts to some extent).
Another idea from Paul: maybe this increased/expanded consciousness would enable someone to more easily develop psionic abilities.
Also: can people infected with the virus communicate with each other? Can they affect the emotional state of the Fearful? Why shouldn’t it go both ways? How did the Fearful react to the other sentient races on Earth originally? Perhaps they do remember encountering other sentient life; then they would be less surprised to meet them again later. The only question is whether they remember creating humans after all this time – it is potentially more interesting if they have forgotten.
Once the PCs meet them, it’s possible there could be a friendly period, depending on how many mystics there are, whether the Fearful sense that right away (although with an oddly fanatical air to them, due to their strong inclination toward religion). Once they find out that some humans use mystic energy, they will freak out and cut off all communication with the PCs. When they find out the PCs can seed mystic worlds, they will go totally ballistic and make war with the Terrans, unless the conflict can be avoided somehow. If all goes as planned, the PCs will come to believe that the Fearful are responsible for the destruction of the outlying colony, since they will pose questions such as, "Have you heard the screams?" Eventually, they will learn of the true Destroyer and the Fearful’s terrible plight thousands of years ago.