Before we dive into the wonders of the spirit world, it is necessary to explain the categories that ghosts will fall into. There are 7 Classes that paranormal beings will fall under, so here they are as follows:
Class I ghosts barely count as a definite being, intangible presences that do not do much beyond merely existing. Their hold on the mortal plane is weak, and as such the most a Class I can do is create odd lights or sounds. Class I spirits can be dealt with by the Ghostbusters, but due to their benign nature this is never really required.
Class II ghosts are similar to a Class I, albeit slightly stronger in power. They may partially manifest in our world, as floating hands, mouths, or a limitedly possessed object. Like Class I ghosts, these anomalies are ultimately harmless, although they are capable of fighting back in a small capacity if confronted.
Class III ghosts are the first category that are in some way definitively human, but their form can vary from clearly that of a person to a freakish version of what they used to be, and their identity is a mystery even to them. They are usually not aggressive but are difficult to handle and will retaliate if met with violence. If a Class III learns of its true identity, it will either peacefully disperse or cling to the mortal world and become more dangerous.
Class IV ghosts are the spirits of humans whose identity is known and their appearance is a perfect, albeit spiritual recreation of their living self. Class IV ghosts are fairly common, and their level of threat can vary wildly, as they can obtain incredible levels of power. Being former humans, some Class IV spirits can be peacefully dealt with by helping them complete unfinished business, come to terms with their death, or in some way make peace with their regrets/grudges. Failing that, I suppose calling the Ghostbusters isn't a bad idea.
Class V ghosts are perhaps the most common of all, being bizarre monstrous spirits that aren't connected to a living being at all, but rather manifestations of strong emotions or major events. Their behavior is formed based on the occurrence that spawned them, but they will usually become violent in some form regardless. Most would describe them all as hideous, I say they are cute. Well, in any event, a call for the Ghostbusters will likely sort one of these fellows out.
Class VI ghosts are the spirits of animals, simple as that. The reason for an animal returning as a ghost seems random, but they will act almost the same as when they were alive. As a result, a violent solution is not always needed; treating these specters with kindness as with living animals can provide results, but in more difficult cases outside help will likely be needed.
Class VII ghosts are the most dangerous of all, universally consisting of preternatural beings of ultimate power. Demons, gods, and deities, all those apocalyptic horrors in between. They tend to be very intelligent along with their strength. If you find yourself confronted with one of these beings, inform the Ghostbusters as soon as possible, run for your life, and pray that you survive.
With that said, let us now examine the ghosts and ghouls of the world…