Out of all the peoples in all the Worlds, the most feared are not the element-wielding Alutians, the mystical sorcerers of Coranth, the animal-like beings of Lehr, or even the wealthy and political Vyltians. It is the Fearans.
Part of the problem is their isolationist tendencies. They interact with other cultures only at the most basic and necessary of levels required by government and trade, keeping to themselves and denying any attempts at integration. They are the only race which has never spread in any significant numbers beyond their original world - in fact, aside from a bare handful of oddities of character, the only Fearans ever to be found outside of Saelis have been exiles and criminals, most frequently those who have abused their power. As such, most of the Fearans who have interacted directly with other races are either those of less than savory natures, or else those who, for all their wanderlust, still carry with them remnants at least of an ingrained cultural emphasis on privacy and isolation.
The other part of the problem is their powers themselves. Fearans hold a unique ability in the world, unmatched even by the most creative of Corian sorcery: they hold the power of life and death itself. Any Fearan can sense the presence of living things, an ability which would be considered uncanny even on its own. Furthermore, once a Fearan reaches a certain point of maturity (most often pre-pubescent, averaging ten years of age) he or she learns how to direct the flow of life through their own body, either drawing it in from or pressing it out into a second party. As such, it is very possible for any Fearan to, with little more than simple physical contact and to their complete benefit, drain a hypothetical victim of the very energy that they require to live - a possibility which is very easy to fear, however rare or unfounded it is in reality.
In actuality, Fearans most revere the concept of balance, of drawing in no more than one lets out and vice versa, of maintaining a state of neutrality. Their beliefs demand that they neither drain any living thing to desolation nor to invigorate any dead or dying thing to animation. Other peoples may know of this system of belief and culture in an intellectual way, but the vast majority still regard Fearans as unnerving at best and unnatural at worst.