Astral Hypnos is a status-changing spell that puts the target to sleep for a maximum duration of ten seconds. During this period, the target cannot perform any actions.[1]
However, if the target receives any damage during this period, the effect of the spell is cancelled.
Because the cooldown period for Astral Hypnos is only 5 seconds, it's possible for a skilled Enchanter to keep two enemies incapacitated simultaneously by repeatedly recasting the spell on both. Certain equipment can make this spell even more effective, hypothetically allowing a skilled caster to keep even three or four opponents frozen at once.[1]
The Freezer build focuses on the usage of Astral Hypnos as a crowd control technique; this is the type of build Nureha uses.[2]