Masiteb

The Masiteb is a theological concept in Zesheko religion, meaning "second body" or "shadow body." It is essentially the idea that a person has a second ethereal body that exists alongside their body and soul but in the Astral Plane (or realm of Alima). This shadow body is borne from a person's innate ability to articulate new vessels for one's soul and self, just as Alima formed three new body-vessels for themselves to interact with mortalkind. When a person dreams or experiences out-of-body sensations, this is believed to be the Masiteb in action. When Leviathans commune with dreamers in the Astral Plane or Lunar Gods use a Dream Contact, this is believed to be a 'Masiteb meeting' in which the mortal soul protects itself from spiritual entities by forming its Masiteb defensively.
Masitebs also serve a critical function in their ability to absorb and divert pollution from the physical body and soul. As bodies formed of a kind of "spiritual quicksilver", they are simultaneously physical and liquid - fluid and constant. While impurities collect in the physical body (from its nature as solids-and-liquids-in-conjunction) and taint the soul (as pure and essential fluid), impurities naturally glide off the Masiteb and any that do accumulate can be easily cleansed by rituals. Pollutants from necessary-but-impure acts can be diverted to the Masiteb by shifting a portion of one's consciousness to it. This is done by entering a slightly altered mental state, marked by feeling "other than one's self." This mental state does not require substances but is often entered through forms of communal ritual and changes in social standing. For example, the Masiteb is a crucial part of the "partial death" mentality that soldiers embrace in Holy Zeshema, where they see themselves as existing outside of their body and living as a new person haunted by their old self in isolated communities. This process can be reversed, allowing for peaceful reintegration without the baggage of impure violence (and externalizing any trauma or guilt). 
The Masiteb also has an active and positive purpose: it is seen as a way to explore dreams, prophecies, and spiritual dimensions removed from the physical body. This can also enable people to revive their bodies and improve their "inner selves" according to popular mysticism. 
Articulating a Masiteb is essentially mastering one's ability to detach from the body and one's sense of self, to construct a new persona or mental self to inhabit as genuinely as one's previous self. This can also mean detachment from pain, desires, fear, or attachments. This disconnection is not permanent, but intentionally temporary. It is not magical in a traditional sense, but it does seem to confuse and disorient Purgatory somewhat for those Zeshem that are sent there.