That son of Nyx, whose Roman equivalent is Somnis, was aided by Morpheus.  
One deity who ruled over this phenomenon possessed a necklace with 130 golden balls, took the form of a swan on a lake named Dragon's Mouth, and inflicted it on Ireland after eloping with her lover. In Japanese tradition, rituals to ward off the influence of the Three Worms on Koshin days were marked by avoiding this phenomenon, associated with Caer Ibormeith. In ancient times, people known as Seekers would travel to (*) Incubation Temples designed for and named after this practice, which were often dedicated to either Imhotep or Asclepius. The Greek deity associated with this concept was sometimes depicted with an inverted torch as a winged young man and resided in Erebos, a land beyond the reaches of the sun. That son of Nyx, whose Roman equivalent is Somnis, was aided by Morpheus.  For 10 points, name this phenomenon presided over by Hypnos, whose most prominent mythical practitioner may be Rip Van Winkle.
One deity who ruled over this phenomenon possessed a necklace with 130 golden balls, took the form of a swan on a lake named Dragon's Mouth, and inflicted it on Ireland after eloping with her lover.
sleep [accept dreaming during the first two sentences, prompt thereafter]