It is a fact of life on Ravnica that, more often than not, death is not the end for a weary soul. When a person dies, their spirit tends to linger for a time on the material plane as some sort of ghost – be it through guild obligation, unfinished business, or simply because the laws of nature make them. The amount of time varies as often as the factors of the ghost’s existence, but all souls eventually fade away and appear in Agyrem once their business is done, although that business can sometimes last centuries. Some maintain a semblance of their former selves, while others devolve into strange phantoms and specters, devoid of most everything that made them an individual.
In truth, the only common factor about ghosts, apparitions and other haunts on Ravnica is their frequency. Be it some lost soul slipping through a darkened alleyway one night, an Orzhov phantom working off a crushing debt from beyond the grave, or one of the Azorius Senate’s loyal and lawful Soulsworn, spirits are frighteningly common on the plane.
The ghost described in the Pathfinder RPG core rules most resembles a Woundseeker, a dangerous spirit that returns from the grave because of its intense emotions. Woundseekers attempt to find the source of their trauma, generally lashing out at the world around them in a blind sorrow or rage. However, the typical ghost rules can be used to fit all sorts of spirits, and many other incorporeal undead, such as allips and spectres make their presence known in Ravnica.