Deep Sleep

 disables the Chat Box, causes 2% of maximum HP/SP is recovered each second, and causes damage from the next attack to be amplified by 1.5.

Abilities
The following abilities inflict :
 * Deep Sleep Lullaby
 * Arrullo

Cure
can be cured through the following methods:
 * Royal Guard's King's Grace can remove the effect.

Prevention
The following lists ways that can be prevented:
 * Base level and INT reduce the duration.