Dreams allow us to be free from the hardships of reality, but even they can become nightmares that will consume us if were are not careful - Dream Seer
Bringers of CorruptionEven the most peaceful of places, such as The Dreaming of the Hidden Realms, are not immune to the power that is The Gloom whose reaches to all places where darkness resides. But even it has only so much power over the hidden realms that it must send its servants to create nightmares to torment all those that sleep with the Dreaming to torment and corrupt them to its will. These nightmares are created to prey upon the fears and regret of the people that will slowly turn into Gloomspawn while the Gloomification process is done while these nightmares trap them. Even when they wake they will continue to process every time they sleep until the transformation is complete. While all are susceptible to the power of nightmares, the ones who are targeted by them the most are children. For children are the light of the world, full of wonder and enchantment, they believe that they can achieve anything if they believe so. Their dreams are often the brightest and most pure that the Dreaming glows brightly whenever a child dreams, keeping away the power of the Gloom from ever expanding into it. But because of this, nightmares can easily prey upon them, for they are often the least suspecting of the dangers that may come with their dreams. It is here that they corrupt and drains away their light so Dreaming becomes weaker and weaker as the nightmare's hold can bring about the coming of their master.
All nightmares exist only in The Dreaming, one of the Hidden Realms where all creature sleep and dream to unburden themselves with the troubles of the waking world. It is here that they stalk and prey upon all that they manage to catch to corrupt them with their power. But beyond the Dreaming, they have no real power beyond it nor can they travel across the Hidden Realms or into the Waking World.