Dream Realms are a species of multidimensional parasites that harmlessly feed on the imaginations & creativity of their hosts, in order to create new universes, and thus characters in those universes, for future generations of parasites to feed on. At their base form, Dream Realms may appear to their hosts as an endless void of colour & distant stars. Hosts enter these realms simply by falling asleep. When in these realms, the host can basically... do whatever they want, much like your standard lucid dream. Some meticulously draft up vivid scenarios & act out power-fantasies. Some just don't bother & continue sleeping like normal.

  Unlike your standard lucid dreams, however, aside from the obvious difference of, y'know, actually creating whole other universes from your subconscious, Dream Realms also allow for the host to invite others, even non-Dream-Realm hosts, to their realm, as long as the other subjects are sleeping. Imagination from anyone other than the Dream Realm's host does not create new universes or characters, but it does help to fuel the Dream Realm's power.

  Dream Realms are permanently entwined with their host's mind, and will die when their host dies, though their resulting creations will remain. The physical bodies of Dream Realm hosts also tend to be more vulnerable to possible danger when asleep, as it is difficult to wake them up by force, meaning they need to wake up on their own.