Corrupted souls are the souls of people who committed crimes against the cycle of life, the soul of the user is corrupted according to the number of crimes, corrupted souls are unable to pass to the afterlife and therefore contaminate the spectral world with their poison.
The Mediums are people capable of interacting with the physical and spectral world, to become Medium is necessary to come into contact with a Soul Reaver and form a pact with him, the Medium share certain abilities with the Reavers, such as feeling the souls or travel in the spectral world.
The possessed bodies can be from objects to physical forms similar to humans, the pure souls are able to reside in an object to move through the physical world, to enter and exit the object is necessary the help of a Soul Reaver as the Mediums do not have this ability.
The pure souls are the essence of the human being, this type of souls are possessed by people who have not committed acts against the cycle of life, pure souls can manifest in a semi-physical form but only in the spectral world, besides being able to pass to the afterlife.
Soul Reavers are soul collectors found in the spectral world, they are the only beings with the ability to interact in the physical world, they also have several spiritual abilities such as feeling the souls of others, separating the soul of a person from their body with their consent, entering the minds of people, possessing objects, being able to see the physical world, among others not known.
Shadows are disembodied representations of people who are still alive, they can only be found in the spectral world, the shadows will be denser depending on the bond you have with the respective person.