Sleep (ability)

Sleep, previously spelled as Slep, is a magic spell in Final Fantasy Adventure and Adventures of Mana. It is learned by reading the Book of Sleep obtained by defeating the Vampire in Kett Manor.

Final Fantasy Adventure/Adventures of Mana
Sumo receives this spell after slaying Count Lee atempting to stop the hero from rescuing Fuji from his grip.

Description
Put all monsters on screen to sleep for a limited length of time. However, some monsters are immune to it, and some enemies will continue to attack by weapons or magic while under the spell.