Hypnokinesis

Hypnokinesis (from the Greek word hypnos, meaning sleep) is the ability to manipulate sleep patterns and even dreams. This can be used to induce instantaneous sleep on biotic subjects, or to induce perpetual insomnia (which in a few days can kill you). One with this ability can remove the need to sleep from any biotic subject, or make them dreadfully tired all the time. One can also cause the subject to sleep forever in a comatose-like state and can even determine how deep a sleep or how long a person or people has. This has been proven to be a very powerful type of magic, as proven in The Last Olympian.

The Last Olympian
About two months before the start of the book, Grover while in Central Park sees Morpheus walking around and puts Grover to sleep for two months before Percy and Nico wake him up. Later, right before the Battle of Manhattan, Morpheus places a large sleeping spell over the entire island of Manhattan causing everyone, but demigods, gods, Titans, monsters, and clear-sighted humans, to fall asleep.

The Lost Hero
When Annabeth walks into Hypnos' cabin to get help from Clovis, Jason finds himself falling asleep and Annabeth warns that if he falls asleep inside the cabin, he may never wake up.

The Son Of Neptune
Percy is said to have been asleep for a long time. This deep slumber was result of Hera's magic.

Abilities
The general abilities of Hypnokinesis include:
 * The ability to put people to sleep.
 * Astral projection/dream travel, as in The Lost Hero, Clovis, son of Hypnos, says to have met Michael Jackson in his dreams.
 * May be able to manipulate dreams, since dreams are a part of sleep.

Users of Hypnokinesis

 * Hypnos
 * Morpheus
 * Clovis and the other demigod children of Hypnos/Somnus
 * Hera (to some degree)
 * Hades (to some degree using shadows)
 * Nico di Angelo (to some degree using shadows)
 * Bianca di Angelo (to some degree using shadows)