Observer

An Observer, by simple terms is someone that assists in seeing all the possiblities that occur in the world of Blazblue due to all the time loops that happen because of the Master Unit: Amaterasu. It is unknown how one actually becomes an observer, but it is implied that one can be given the position by Takamagahara, by having some degree of power as the known beings that are observers are the series most powerful characters story-wise, or by becoming an "uncertain factor" in the time loop which you exist in. It is also shown in Hakumen's story that someone can actually agree to be observed by another individual. The idea of an observer is based on quantum physics and the experiment Schrödinger's cat. Special beings like Hazama, Hakumen or Rachel will disappear without an observer, though apparently Ragna's hate for Hazama is enough to maintain the latter.

List of known Observers
 * Rachel Alucard (relieved of position, now only observing Hakumen)
 * Kokonoe (temporarily, was observing Hakumen)
 * Saya
 * Noel & Mu (μ-12) (out of commission)
 * Takamagahara (no longer able to observe due to a virus)