Vestigehood

What happens when a god... dies? Well... I don't plan to experience it myself, but it seems that when a god dies they don't just vanish. Their soul doesn't just go to some other dimension, like mortal souls do. Say what you will about us, but we gods are stubborn things. And when we die we linger on. As vestiges. 

-Althos, in a private conversation with an angel of knowledge regarding the final fates of gods.

In A Solitary God In A Dark Multiverse, all things could die. Not even the gods were immune to death. In the unspeakably distant past, the era known colloquially as "The Mythic Era", the deaths of gods were remarkably rare events, but the unforeseen apocalypse that ended that era killed thousands of deities. 
When a god dies, their souls may be destroyed, but they linger on, in a new, vastly weaker, but still tremendously powerful form. Vestiges are, for the most part, confined to a final gravesite, sometimes one that appears spontaneously when they die, but oftentimes their gravesites are places that were tremendously important to them in life. 
In the mythic era vestiges were frightening but manageable echoes of gods, ones whose presences could have all manner of strange effects on the areas surrounding their gravesites but who tended to be handled by gods and other higher beings. But when thousands of gods perished virtually at once, in a multiverse without other higher beings to handle the chaos of the emergence of thousands of ghost-like beings with deific levels of power, the rise of vestiges was a calamity that in at least one case resulted in an entire layer of a dimension being destroyed for hundreds of thousands of years. 
A vestige is an unspeakably powerful, often angry, being. Encountering them is often the last mistake mortals make if they can even penetrate a vestige's gravesite, which if done is itself a sign that they are among the most powerful examples of their kinds as vestiges are often surrounded by some of their most powerful servants from when they were alive, fanatics who willingly forsake their lives to tend to their gods in death. 
Author's Note: This is a living article that can and will be edited as more and more information is revealed, in the story, about vestiges.

Transmission & Vectors

This condition afflicts presumably all gods. It appears to be species-wide, and is something present in all gods, even when they themselves were not born as deities but became a deity through some other means. It is not contagious and very few species possess the power to automatically become undead beings upon their deaths.

Causes

The cause of this condition is unclear, even the system itself appears not to understand precisely what causes it. That said, the condition under which it is triggered is the death of a deity. That much is clear.

Symptoms

When a deity dies their bodies vanish. Their souls dissipate into aether. But they are not gone. At least not entirely. The divine energy that flows through them leaves the area of their deaths and returns to a place that is significant for them, a place outside of their divine realm where they held some sort of real power. The divine power that lingers in them is then partially spent either building a gravesite, or outfitting an existing structure with the appropriate power to serve as one. And then the rest is used to give them new bodies that matched theirs when they died.

Treatment

There is no treatment, aside from the execution of the vestige. Though that said, vestiges themselves vary in alignment just as much as gods do, and though vestiges tend to be angry when they awaken and find themselves as close to undead as is possible for a deity they can and have been known to mellow out over time and often revert to their old alignments over time. Though it is possible for death to change a deity, and sometimes deities take on whole new traits or even change their alignments, even hundreds of millennia after death.

Prognosis

The condition, barring someone or a group of people, killing the vestige is eternal. Vestige-gods can live eternally just like true, living gods could. The condition is as close to fatal as is possible for a deity, or rather as opposed to fatal, it is something worse for a slain god: eternal.

Sequela

Deities lose a tremendous portion of their power, the overwhelming majority of their connection to the system, and some deities are even forgotten altogether as death takes them, for a moment. When they come back they are weakened, even overgods are vulnerable to this reality and even they do not retain their level of power or influence when they die. That has an impact on a god's psyche, one that only the oldest vestiges have begun to get over.

History

If any deities have perished and not become vestiges it must have been before the age of Anthem, a truly ancient overgod of reality and law, created the system. It is possible, and terrifyingly indeed, probable, that this condition has always affiliated the gods. If so that means that every single dead god either has or had a vestige at some point in history. Until the spontaneous emergence of Althos every god had died, and so it would logically follow that... every god who has ever lived, aside from Althos, has or had a vestige, somewhere in existence. 
Some are known to dwell in Infernius, and others are known to dwell in the Heart of Darkness. Some are even speculated to exist in the land of the mortals. Thus far two have been confirmed to dwell in the realm of mortals. One has even taken a world for its own.

Cultural Reception

Mortals, in their ignorance, are often blissfully unaware of the existence of vestiges. Most vestiges lurk in their unassailable homes, doing only they know what in their strange palaces and fierce gravesites. How extraplanars feel about vestiges depends on how they felt about gods in the first place. Abominations are... either resentful of vestiges or adore them, depending on where the god in question fell along the "reality-vs-eldritch" spectrum.

Type

Divine

Origin

Divine

Rarity

Extremely Rare

Affected Species

• Deity