[2] The character is depicted most commonly as a major enemy of Doctor Strange and Ghost Rider.

[5] Nightmare has encountered Spider-Man, Captain America, Ghost Rider, Dazzler, Wolverine, the Hulk, and Squirrel Girl on different occasions.

Nightmare sent Sleepwalker back to his own realm, with a monitor to assure the hero Rick was not being tormented.

Many people who were deeply patriotic or had achieved a degree of success through hard work were going on violent rampages.

Hercules and the others escape his realm, having stolen the map via trickery as Mikaboshi had created a shadow duplicate of himself to fool Nightmare.

[12] He later plots to conquer the entirety of fiction, adding it to his realm of nightmares, but was defeated by the Fantastic Four.

He travels to Nightmare's realm while they are trying to torment Hercules with visions of Amatusu-Mikaboshi and quickly defeats the demon.

His apparent death is felt by those who have psionic powers and it is later revealed that those who fall asleep enter into a state of berserk rage.

Nightmare wants to fight the Serpent, but Mephisto talks him out of it, citing that he will lose all respect from the other evil gods.

Nightmare, unsure of what to do, listens to Mephisto when he advises for him to do what everyone else is doing: stay neutral, and wait for something else to happen.

Nightmare was later seen tormenting Loki as part of a plan to garner greater powers in The Terrorism Myth storyline.

[17] With the recent demise of Doctor Strange, several mystical threats were able to freely move into position to try and doom the world of man, including Nightmare, who quickly finds himself in New York where he confronts Cyclops, Jean Grey and X-23 during their sleep.

Nightmare is a virtually omnipotent entity who rules the Dream Dimension and can draw power from psychic energy in subconscious minds.