Dirge of Worlds

For every beginning, there must always - one day - be an end.

— solemn scholar

The Dirge of Worlds is an ending to many stories, and a beginning to countless others. It is the collected events that end a planet, to describe it to a child; it is death on a scale incomprehensible. It is often assumed to be the reason behind a world's destruction, when this could not be farther from the truth: the Dirge of Worlds is not the cause.
It is the symptom, not the sickness; it is the response, not the call.

Fiery Demise by Hanhula (via Midjourney)

It is the end and a beginning. It does not write the events leading up to its own occurrence.
Though every planetary body is different, those that can be accurately described as worlds - solid planets that contain sapient life, usually - are formed with remarkable consistency in their innate magical composition. They may have entirely different sizes, elemental compositions, and behaviours to one another, but on magic's level, each world is every other world's sibling. Their beginnings are identical from magic's perspective; the dirge, as their end, is thus also their constant.
Once the a world has begun to experience its dirge, it is possible to slow down or even entirely halt the process. The damage dealt can be repaired, given time. Magic is a replenishable resource; no damage is truly permanent where magic permeates, not given sufficient time and motivation to repair it. However, no world can be spared its fate forever. Sooner or later, mortal efforts will fail. And their planet will die.

Cause of Death

Nothing just... stops. A world can't just end, there's got to be some reason why!

— desperate mortal

In truth, nothing is certain about the beginnings of a world's final dirge. The potential causes are myriad, stretched across spans of millennia; determining what the final nail in a coffin large enough to contain a planet was would be nigh impossible. With that said, there are certainly causes more obvious than others. World-spanning plagues are an alarmingly frequent cause: the crystalline horror that has pursued the elves across space is perhaps a more literal plague, presenting itself by the utter crystallisation of all life.

A dirge may naturally be triggered by a world's own nature, if events of sufficiently apocalyptic degree trigger at the same time and cause too strong of an impact on the planet's leylines. Supervolcanoes are the most likely trigger of these.
External forces may also trigger a dirge, given sufficient power. Solar flares, planetary collisions, or impact events with significantly large meteors can damage a planet enough to the point of its magic becoming permanently damaged, thus causing the potential beginning of a planet's dirge if the ley network cannot recover fast enough.
However, it is magical intervention that is far more likely to cause the end of a world. The actions of deities can all too easily scar a world, and under their prolongued attention, they may outright destroy it. Though their own rules now prevent direct deific intervention, a particularly strong Champion or Herald might still be used by their deity to bring down the apocalypse.

Supervolcanic Eruption by Hanhula (via Midjourney)

Mortals are not generally capable of triggering dirges on their own, even with powerful magic behind them. Arcane magic provides strength enough to trigger grand apocalypses, but no arcane mage alone has yet triggered a dirge. It is collective mortal irresponsibility that can trigger a dirge when compounded across years, through magic or mundanity. Destruction of natural climates, spread of deadly pandemics, overexploitation and exhaustion of natural resources, and outbreaks of horrific globe-spanning war may all compound upon a planet to trigger a dirge, even with no magic involved.
Magic, while a boon, only speeds up a world's demise, in the end, when given freely to mortals. The dilemmas around this - whether mortals should hold access to magic, whether such a thing is right - were the source of multiple divine wars, and remain sources of tension on many worlds today, even if most do not realise the full reason and consequence behind the debate.

Symptoms

When a person is sick, one can always tell... but the world is always suffering in some form. What turns tragedy into finality?

— worried druid

At its core, the dirge is the steady collapse of a planet's natural magic - its leylines - and the elimination of all life on the planet. Symptoms late in the cycle are predictable - obvious, even - in their destruction; it is the earliest signs of a dirge that are the hardest to spot.

Land's Grief by Hanhula (via Midjourney)

First comes the impact on the living, particularly those in tune with nature in some manner.
Druids and particularly-astute animals, avatars and sensitive mortals - or none of these at all in favour of different folk altogether, if the dirge is more unnatural in nature. These afflicted souls experience odd disturbances in reality as the planes bleed into one another in their vision, as magic distorts to present visions of what may be, and as their dreams are plagued with omens they may not understand.
They experience unsettling feelings with no natural origin, and find themselves drained of energy faster than has ever been normal. They may sleep far more than their kin; they may also be prone to headaches, illness, or fits of emotion.
Nature's slow descent comes next. Weather patterns become steadily more unpredictable, with seasons meaning less and less as the dirge progresses.

Snow may come to burning climates; scorching heat may come to glaciers. Seismic activity and volcanic activity increase in step with one another, worsening the effect on weather as volcanic ash clogs the skies. The planet's seas shift in their strength, becoming far more violent in some areas, and utterly still in others. No reason guides their movement. Not now.

As mortals struggle to inhabit this mess, magic itself begins to fray. Areas of null magic and wild magic form in reckless abandon, often tearing along the paths of leylines.
Magic's reliable predictability becomes a burden; those relying on it for vital tasks like the growth of food or provision of water will soon struggle as the damage worsens.
Magical abilities that tear through planar barriers, like teleportation and summoning, change in odd ways during the dirge; on rare occasions, the magic may attempt to whisk its caster to safety, or prevent the summoning of new creatures to the dying world.
Even the planet's orbit shifts during its dirge. Its own gravitational pull twists and changes. If the planet is tidally locked, the lock may fail entirely, often causing the planet's moon(s) to either be lost to space or to collide with the planet in devastating force.

Snow in Summer by Hanhula (via Midjourney)

The planet retains enough of its own gravity to hold its mortals, but can do little else; it is carried along by interstellar gravitational forces rather than asserting any pressure of its own.
All of these effects start out as absolutely minor impacts: a small increase to bad weather, an occasional mention of an odd dream, a single spell that fails. It is when they go unnoticed and grow far worse that the terrible realisation sets in for those aware of the dirge. By that point, they must hope that their societies are strong enough to stall and stop the dirge - or, failing that, that they can flee to another world.

Leyline Lamentations by Hanhula (via Midjourney)

Type

Metaphysical

It is in the tales of those who have travelled far beyond our planet that we first learnt of the Dirge of Worlds.
Until we confirmed its effects with the eldest of elvenkind, they who fled falling worlds themselves, we thought it myth.
Gods, spare us this fate...

— uneasy scholar

Of Istralar's End

Istralar has endured threat after threat in its lengthy existence, and its time in the multiverse stretches back before history can be easily recorded in the words of mortals. She is an older world, and she wears her scars well.
Many of the events that could cause a dirge have already happened, sometimes many times, to Istralar.
Gods have warred across the surface, leaving scars like the Sunari Wilderness and the Starsear in their wake. Corruption still spreads in the wake of this ruin.
The Worldrend saw Terra Arcana succumb to its own dirge as it exploded in Istralar's skies, polluting the planet with deep-seated corruption from Terra Arcana's death throes.
Mortals wage wars of ever higher stakes; some nations, like Vexua, have found and tested weapons beyond understanding.
The Shards of the Void ply their fell curse across the planet's surface, killing millions across millennia as the world slips further into their grasp.
Leyline wounds fester in the Heartforge of Iskaldhal, unbeknownst to most of Istralar's inhabitants; it is the largest of Istralar's festering wounds, but not the only of its tragic kind.
Now, the Earth-Mother's Gift - a Shard - has been repaired through great damage to the ley nexus within the Sea of Souls...
Can Istralar weather this latest tragedy, or are its inhabitants doomed to die as their world fails around them?

Our world is wounded. Bleeding, even. But in its final years, as the end draws closer?
I think not. Not in this age of Champions.
The gods would not forsake us... right?

— nervous warrior

Interstellar Devastation by Hanhula (via Midjourney)

Dead Worlds

Song of the End by Hanhula (via Midjourney)

No life left to mourn a world... It's hard to fathom.

— shocked adventurer

A dead world is a world that has been silenced by its dirge. No natural life still lives on the planet; any avatar it once held is dead alongside the beings that inhabited it. Unless it was destroyed in the force of its dirge, the world itself still hangs in space to await the natural fate of all planets. It is nothing more than a sphere of silence.
Some particularly powerful mages have made attempts to revive dead worlds, or to utilise them for their own purposes. Alas, it is not as easy as they would believe.
With no leyline network and no connection to natural magic, these worlds receive no shielding from the dangers of the universe. No life can persist without nature's strength; visitors to dead worlds find them draining to stand on as whatever latent energies lurk in the earth beneath their feet seek to consume the spark of energy that has alighted on them. Those that can resist this draining effect are yet exposed to corruption from space itself.
Deities are known to be capable of reigniting life in a world, just as the most powerful of them can create a planet; this is known to be some of the strongest magic that exists. No champion or even demigod can handle the sheer power involved in a planet's birth. No history exists of deities creating planets in the past few millennia, though historical records provide proof of the ability through planets like Terra Arcana and Aetharis. The gods are notably silent on the topic of how such creation magic works - by general accord, this is to prevent mortals from attempting to figure out the ability themselves. Demiplanes are more than enough.

It is possible that all planets may have once been created by deities. No proof exists to serve this assumption - but what other power could have created the universe and all its planets?