Coming into existence in the same primal era that brought the first beings, when thought an fury an dream first took shape - the first Quori came into being. The immense mental capacity of the first creatures lay down the foundations for the ethereal plane, a space that can live alongside but detached from the material. As the first creatures took their first steps or flapped their wings for the first time, the psychic jubilation created the first Quori specters. These creatures are immaterial but can take on & inspire the material creatures around them. As the world began to age, various concepts and creations and dreams created more & more Quori that could only watch from beyond the thin glass veil. Over time, many of these Quori learned that they had similar traits to another material being - the Azerai / Ziggurani. The Quori learned to take on different shapes, and connect with likeminded individuals. First influencing or mutating the smallest creatures, but then growing in comfort with the lowly creatures who seemed powerless but through mental practice, training, and dreaming, could influence this ethereal plane so much more. These Quori have influenced MOST bards have inspired many a Wizard and have whispered into ALL types of people that have walked this plane. In this day & age, SOME of these Quori are able to LINK themselves to people of/under specific conditions. This mental link and soon enough cohabitation with OTHER Quori and creature combinations created the first Kalashtar - those able to walk between the material & immaterial, those that can take dreams & psionics and either give them form or dissipate them.
But of course, not all dreams are a comfort to everyone. Some Quori have sought less to coexist and more to control, OR those who have touched humanoids with far darker desires have taken on such mad delusions of believing that they can take form on the material themselves, or simply traverse onto it in their amorphous madness-inducing true forms. Worse off, they are psionic creatures of thought and mind, it is not impossible to actually do it. So has there been a secret war fought only between the unwaking hours for inspiration and dream to combat disenchantment and nightmares.