CDI System

**Corporeal Density Index System** (体密度指数システム), also shortened to the **CDI System** (CDIシステム), is a classification system commonly used by occult hunters for supernatural entities, mainly ghosts and spirits.

## Classifications

### Class I

Entities with undeveloped forms, insubstantial, and difficult to see. Interaction with their environment is limited and enigmatic (i.e. spectral lights, voices and sounds, ectoplasmic vapors...). Beings of higher forms may originally appear as Class I entities prior to full manifestation or draw the presence of Class I entities, serving as an indication of the presence of true supernatural phenomena. Simple application of a proton stream is normally effective for complete dispersal.

### Class II

Entities with an awareness of time and space. Class II entities and up can physically manipulate things in this plane of existence. These forms are vague, inconsistent, or incomplete (i.e. floating sheets, ghostly hands, animated lips...). Although a proton stream is normally effective, some Class II entities can return attacks so caution is advised.

### Class III

Anonymous hauntings. These entities have a distinct human form and personality, but their former identity as a living being is not established. Alternatively, these entities are humans with a warped sense of identity or impartial corpus. If identity and form are established, the entity is reassigned as Class IV. These entities are often difficult to deal with and often possess sophisticated means of defense. This class is also used for the ghosts of animals or of non-sentient, non-sapient spirits.

### Class IV

The entity's true identity is intact. These entities have a distinct human form and personality with known identity, akin to that of a low-level shade. Economic disposal methods include research into said entity's background and surrounding legends. Communication may be reached through a séance. Research indicates a folk ritual of salting and burning the entity's mortal remains often proves as effective as proton streams and traps.

### Class V

Ectoplasmic manifestations of definite but non-human form. Class V entities could be formed from emotionally-charged events or as side-effects from ritual summoning. These typically require extensive proton stream implementation to sap their considerable ectoplasmic reserves to allow for capture in a Muon Trap.

### Class VI

Parahuman interdimensional beings of significant power. Known by many names: faerie, demon, daimon, shade, etc. Range of power varies. May be resistant to singular or even multiple proton streams, and may require prolonged exposure to three or more proton streams for sufficient weakening to allow defeating, trapping, or banishing.

### Class VII

Exceptionally powerful entities exhibiting control over reality, time, space, or the classical elements. These are often identified by primitive cultures as Pagan Gods, Angels, Devils, Greater Spirits, or other elevated forms of a Class VI entity. Entities which fit this classification often have harbingers or minions. Neutralizing such beings is usually a problematic undertaking at best.

Most standard procedures are futile. The most realistic plan is to take measures to prevent these beings from entering this reality in the first place. In-depth research about their background, myths and legends, possible connections to other beings, and rituals and ceremonies surrounding them is a must.

## Trivia

* This system is created based on and named after the CDI System from the *Ghostbusters* franchise, as its original creator was a huge fan of the franchise as a whole.