@Kuma, I retired this {{Context}} <!-- I just need context with the Dark Hour in Persona 3 as it been shown and described as a secret hour in time rather than an alternate world. I could be wrong on this and I need context. -->
In Persona 3, while the Dark Hour refers to a "hidden hour" when shadows manifest, in practice it also refers to the realm that can be accessed during that time. Given that in said game most of the human (plus robot and dog) cast with magical and Persona-summoning abilities can only use those during the Dark Hour, it is an alternate realm for the ends of this trope.