True death occurs when the soul is severed from the body. Once a person dies—whether mortal or immortal—their soul drifts away to a dimensional hub known as the Underworld. Those who devoted their lives to a religion will journey farther to the underworld aligned to them and await judgment.
Deities and high-ranking demons may choose to give a soul a second chance through reincarnation, or resurrection in exceedingly rare cases. If a soul is reincarnated it will retain at least a portion of its memories, personality, and appearance. Resurrection allows full retention of all traits. Those that do not experience rebirth are recycled into the universe to eventually be turned into a brand new soul.
Time flows differently, or not at all in other dimensions so there is no way to measure the process. Some may be resurrected immediately if a particular trait of theirs captures a deity or demon's attention. Many wait in purgatory for the equivalent of centuries on Earth only to be erased and returned to the cosmic cycle.
There are those, however, that refuse to accept their death and let go of their previous lives. People with strong emotional ties or important business left unfinished may be able to focus the energy in their souls to manifest in the material world. Powerful curses are also able to deny souls rest by delaying their final passing until a certain condition is met.
Ghosts
The word “ghost” can be used to describe all classifications of disembodied souls, or the simplest manifestation of them. As the latter, it is an echo reaching out across the veil between the Underworld and the material world. Ghosts cannot stray far from their place of death and to summon them by necromancy is a jarring and painful experience akin to being ripped from the womb. It takes a tremendous amount of energy to breach the dimensional curtain and the dead are often too weak and weary to do more than whisper a single phrase incoherently before fading away forever.
These types of ghosts visit mortals quite frequently, but are dismissed as mind tricks and wishful thinking when the soul is too weak to make a repeat performance.
Apparition
Apparitions are a minor improvement over ghosts that can use what little energy they have left to form a hazy image of how they appeared in life. They are usually restricted to either uttering a simple, semi-conscious phrase or manifesting an image, but rarely ever both at once.
Poltergeist
These souls are typically and incorrectly classified in folklore as purely malevolent, when they are actually just ghosts willful enough to make their presence known in a more forceful manner. Poltergeists are another small step up the ladder of the afterlife and the first to be able to affect the material world. They will cause a drop in ambient temperature when crossing over from the wastelands of the Underworld, akin to opening a window in the winter. Beyond limited speech and images of themselves, poltergeists can interact with physical objects to warn, protect, or lash out at people they feel strongly towards.
Phantom/Specter
Phantoms are angry souls that come from those who have been wronged. Their rage is so great that they can return to the material world in almost perfect form. Their verbal and visual manifestations appear lifelike and will fool all but the keenest eye. They will travel some distance from their place of death if there is another location or person their rage is tied to. While they retain no supernatural powers—should they have had them in life—they are still a formidable encounter due to their intangibility and control over their surroundings.
*The word “phantom” is considered a generic and often erroneous title by the undead to describe a ghost. This stems from the Old World phrase “ville fantôme” (ghost town) used for towns sucked dry and left empty by the undead before the time of their exile.
Specters are the karmic opposite to phantoms. Specters are sometimes referred to as “guardian angels” although they have no actual ties to the Celestial race. They can appear in as much detail as phantoms, but because of their humble and giving nature tend to prefer staying invisible and make their presence seem like a stroke of good fortune. Specters make up the second most common classification of ghost after the initial level. This is said to be because these souls have a need to watch over the ones they care for so great that everything else—including their own chance at rebirth—comes second to them.
Wraith
These sinister beings are near demigods of death and nigh-omnipotent in the Underworld. The power difference between phantoms and wraiths can be compared to a candle versus the sun. Wraiths are exponentially more rare than Ancients are to the undead. The requirements to become one are numerous and almost entirely unknown, save for a few wicked souls that took that knowledge to the grave.
Upon death not only does the body begin to decay, but so does the soul. Supernatural abilities are only inherent to the body in most cases and are lost in the afterlife, but magic remains partially ingrained in the soul for those wise enough to prepare. To become a wraith one must have purpose and power. It takes centuries—if not millennia—to amass adequate strength to make a pact with Death once in the Underworld, and even then success is uncertain.
Once one becomes a wraith and crosses over into the material world they must work quickly and efficiently to form a tether. The pull of the Underworld is stronger than any gravity and a new wraith can be drawn back in and robbed of their power if they do not prove to be cunning. For this purpose wraiths will often have their minions from a previous life prepare spells that will aid in keeping them bound to Earth, or the wraith will masquerade as a god or other divine being to trick mortals into doing their bidding.
After a wraith is anchored to the material world and becomes acclimated they will begin reaping souls to pay their part of the bargain with Death. The more souls offered, the more power granted in return. Being that most successful in becoming a wraith are master necromancers highly in tune with death, they can begin creating their own tethers where they so choose as not to be bound to a single location. However, this soon becomes obsolete—a powerful enough wraith can travel anywhere that Death can.
Wraiths cannot be stopped, cannot be killed nor banished for long, and to contain one is a feat of the gods. Most gods choose to ignore them as the trouble they can bring to a god’s flock if angered is a risk not worth taking. The pact with Death grants them expansive control over the dark elements of the Underworld and even manifestations of Death itself to assist in the reaping of souls.