Death & Reincarnation: Everything you need to know about the afterlife
The Setting.
Dead dragons live in the same hills and mountains as before, and can still see all of the plants, but everything is wreathed in fog and they are incapable of seeing the living, unless they are bonded, in which case they will catch the occasional glimpse of the other dragon, or if said dragon is a ghost-speaker. All ghosts can see ghost-speakers, although the ghosts that are farthest gone can only see them as a faint outline in the fog. Dead dragons are also incapable of seeing the dead of other species, unless they shared a particularly strong bond with said animal during their life, in which case they might catch the occasional glimpse. This has led to speculation that different species have different afterlives.
Strength.
The "strength" of a ghost is not measured by their physical strength, but how much they can see. The weakest ghosts can see nothing, hear nothing, and move on quickly (see reincarnation), while to the Guardian Ghosts, strongest of all dragons, the fog clears away and everything is mapped out before them in a golden web. Guardian Ghosts are also capable of reaching ghost-speakers in their sleep, or directing the lives of the living.
Most dragons are of medium strength, and see everything wrapped in fog, without the golden web.
The ghosts themselves.
In the afterlife, all ghosts are in their prime. They have no wounds, no scars, and can run freely and surely, like the wind. (Some legends say that they are the wind.) They can not fly, however, or walk through trees. Grass bends beneath their feet, but springs back up once they are past, for they are incapable of leaving any impression on the natural world. Should a ghost attempt to move a stone, for example, they shall succeed, but will also return the next day to find that the stone has returned to its previous position.
Reincarnation.
In time, all ghosts fade away, with the exception of the Guardian Ghosts. Once they reincarnate, they will have no memory of their previous life, but will have the same gender and personality, but not necessarily the same name. (There are exceptions to the gender thing, and that tends to lead to highly gender-confused dragons.) Occasionally, should a ghost manage to convince one of the Guardian Ghosts that their reason for returning is great enough, they will find that upon their return, although they remember nothing, they have irrational urges to do certain things, such as protect a loved one from their former life. This is very rare, however, for most ghosts reincarnate far, far away from where they were first born, both in terms of distance and time.
Reincarnation is always mediated by a Guardian Ghost, who is there to erase memories of time past and help the dead dragon through the difficult process of rebirth. If the ghost wishes it, they also take away the ghost's old name and whisper a new one in their ear.