Morpheus (also known as Dream) is an immensely powerful being. He is one of The Endless, 7 primal embodiments of the core facets of life that have been in existence since the beginning of time, older than gods. The other 6 members of the Endless, Dream's brothers and sisters, are Destiny, Death, Desire, Despair, Destruction and Delirium. Each has their own realm, and their own specific function. Dream rules over the realm of dreams. Every sleeping person, animal, plant or alien being who dreams rents out real estate in his domain. He spends his time creating dream worlds for people to inhabit, and characters to inhabit their dreams and nightmares. Beyond literal dreams, Dream also holds sway over daydreams, and the inspiration to come from them. Much of history's great music and literature is a product of Dream. You can't really speak of Dream in terms of his powers as such, as they are so vast as to go beyond super strength or speed or whatever. He is functionally immortal, and can do pretty much whatever he wants to when at full power.