Biologically immortal, unless they willingly give up their time in the afterlife.

Ghosts are the final form of many creatures all throughout Zeta's many Realms. When a being dies, their Soul is usually released into the atmosphere, where it floats out into space and, if left alone, eventually disperses. A ghost is formed when a Seraph snatches the soul before this happens and supplies it with additional energy, mostly Neutral Energy, that will cause it to develop its own physical form and become a complete Energy Being capable of its own thoughts, senses, and emotions. The creature retains its original memories and personality, and is deposited in the proper land of The Hereafter.

Unlike other energy beings, a ghost's body is not stable. Energy is always being lost to the elements in small amounts, and if the ghost does not replenish it, their body may fall apart. To combat this, ghosts are supplied special caves that use powerful energy cores to rebuild this lost material, but the ghost must essentially become unconscious to preserve the energy it has during this process. They do not dream while resting in this way, as all unnecessary processes are temporarily halted.

The energy in the soul that granted the original being their powers in life is preserved throughout the rebirth process, so none of their magic is lost. Ghosts also gain the powers of any Energy Being after their new bodies are constructed, though many find it difficult to control the density of their body, given its natural instability.

Each land of The Hereafter emulates the culture of the ghosts' original homes as closely as possible to make sure everyone is comfortable. Concepts like family bonds, punishment of crimes, and independence are thus preserved from the culture of the living. The only exception to this is how ghosts deal with murder. Seraphim do not reconstruct the bodies of deceased ghosts to prevent overcrowding of the Hereafter. As a result, murdering a ghost is tantamount to robbing them of their right to exist, and is considered deserving of a lifetime of torture.

Because ghosts have theoretically infinite lifespans as long as they rest properly, population control is necessary, but largely left up to the individual's choices unless an emergency arises. Most ghosts choose to leave the afterlife behind and welcome eternal oblivion after a certain amount of time, each for their own reasons. Some see it as their duty to ease the jobs of the Seraphim that look after them. Others feel they have seen enough of the afterlife and have nothing left to experience. If dangerous overcrowding occurs, the Seraphim call for volunteers to give up their forms to make room for others.