Ghost

When a spirit is afflicted by some supernatural power, or beset by a curse, they spirit is mutated into a kind of ghost. The nature of the affliction will often deem what kind of ghost they become. In the case of a curse caused by traumatic death, a spirit will more often turn into a poltergeist - a malevolent creature that will continue to manifest until the curse is broken. A spirit turns into a spectre when it is wrenched from the spirit realm into the material through some supernatural means, usually the power of chaos.