Ghosts

People become ghosts after they died and are received in the afterworld by reapers. Ghosts move through the Death World by levitating and hovering above the ground.

A ghost can be "eternally destroyed" by oganis instead of being led to hell. Alternatively a ghost that has all its soul sucked out by hell turns into the Dead.

Ghosts will start to become the dead after being "wounded".

The number of red eyes on the shape of a ghost indicates the amount of sadness people left behind felt at the death of the person. Most have just one or two but Gwangnam had five. Sese had six despite only her mother knowing about her death. The number of eyes also mean the potential power the ghost can receive in the Death World.

If a ghost's shape has only black eyes then it means that there was no one that felt sad when that soul passed.