The Dream Walkers are Nocturna's servants, tasked with watching over the Dreamlands and the First Hell.1 Most of them are descendants of past relationships between Nocturna and some of the gods, including Dvalin and Samekkh; a few apotheosized mortals also stand among their number. As such, the Dream Walkers do not share the evil taint found in most of the other daedra. They can often be found travelling through the Dreamlands, monitoring the dreams of mortals and altering them if Nocturna wants a message to be conveyed to the person in question. Dream Walkers stay neutral in the war between the gods and daedra.
Dream Walkers raised in the Hells are bound to the hells and are little more than evil sprites that are insinuated into the Dream Realms to play havoc with mortals. Some have been mastered by Nocturna and turned to her ends but still retain their minor-demonic natures.
Mortal Dream Walkers come in two types; Heredetary and Spontaneous.
Heredetary Dream Walkers are secretive clans and tend to be quite few in number as it is not a guranteed trait. Their goals, morals, motivations, and actions within the Dream Realm are varied and cover the gamut from benign to sinister. When they disturb the function of Nocturna's realm she often has them slaughtered by other mortal walkers, typically those she has had bound to do her bidding.
Spontaneous walkers arise merely by a fluke of magic and can be a terribly confused lot during their formative years. Typically they overexert their influence on the dreamers they can touch and are put down by Nocturnas agents, or captured within the Dream Realms and bound to her service. Others may come to understand what they are and, as with the Heredetary types, work within the dream realms to their own ends if they do not seek out some agent of Nocturna and enter into her service.
Nocturna worshipers are not inherantly dream walkers or have the ability to exert themselves within the Dream Realms if they can access them at all. Typically they are only able to percieve another's dreams but not influence them, offering advice to the dreamer once they wake.
Rarer still are Nocturnas chosen servants; Warriors who police the Dream Realms to deal with other mortals, and hell-raised walkers, who have earned Nocturna's enmity. These select few are almost always spontaneous mortals who have an inordinate degree of power within the dream realms - such as being able to enter the dreams of others and affect them substantially. Since beings native to the Dream Realms cannot overtly affect a walker (due to the anchor of their mortal spirit), it is left to these mortal warriors to dispatch or train them accordingly. They can also act as agents and actors within dreams when Nocturna deigns to send the sleeper some manner of Omen, their power and strength in dealing with mortal minds far outstrips the ethereal denizens which are little more than illusions. In some cases they can even kill a sleeper within their dreams but this tends to cause a good deal of havoc as this is an attack that kills the spirit rather than the flesh, leaving the empty mortal shell to perish naturally (they never awaken) unless some other hell-being moves into the empty vessel to possess it.
A mortal slain in this manner does not progress to any of the afterlife realms, their soul is destroyed. Naturally this gets the attention of Gods and creates a dangerous situation as the empty mortal body is a beacon to free spirits within the Dream Realms (be they the deceased or hell-beings).