Dying Suns Campaign Setting: (Subnet d6 and D&D 5e)

On the brink of the Third World War, brought upon by greedy oligarchies, a few ships of refugees discover a fragment of a device in a deep cavern on Mars. It is a ring with characters carved into it in no known language. Held up to the sun, the characters glow with an azure light. After much study, it is discovered that it acts as a star map, pointing to the moon of Pluto, Charon.

Corporations and Governments race to create a spacecraft that can transport scientists, engineers, and soldiers to the outer reaches of the solar system, and it is Arkonian-Sendai that manages to do it first, a MegaCorp dealing with cyberspace and city security.

The fragment leads a team of ArkSen scientists to a cave complex near the moon's core, and what they discovered there is classified information. What they did release to the public, however, was the location of The Warpgate, a ring-like device that launched itself into orbit and activated when the fragment was locked into place.

Blue light ripples across the surface, like water, and hints of what wait on the other side flash randomly beneath its surface.

A scout ship was sent through, and it was found that communications were not severed in transport.

The scout ship found itself in a new star system, where three suns slowly circled each other, and the gravity was so intense, the ship crumpled like a tin can.

The Arkonian-Sendai scientists managed to recalibrate the Warpgate, and the next scout ship reported emerging near a blue and green planet about a half size larger than Earth. In further testing, it was proved to be livable, with no sentient species.

With further re-calibrations, more star systems were discovered, and mankind began expanding.

In a system in far off deep space, a ship graveyard was discovered, and through reverse engineering, Arkonian-Sendai clinched a monopoly on technology and ship building. Their fleet is the largest of Earth's, and they claim ownership of four systems.

It is rumored they are working on a system where the same energy that powers the Warpgates could function on individual ships, allowing them, in essence to teleport across the systems in a series of jumps.

Of a note, and just now being brought to light, are the changes some experienced while going through the Warpgate. It seems, about one in a hundred million who have crossed through a Warpgate have manifested strange psychic powers, able to manipulate the elements, darkmatter, or someone's own healing process, accelerating it a hundred fold.
Arkonian-Sendai has begun experimentation on a few of the ones who have manifested these powers, and some of their research is troubling, to say the least.

There are some who are able to heal the most grievous wounds, others are able to gather plasma out of thin air to create fire, lighting, acid, or other substance. Some are able to create shields stronger than any force field around themselves, or to improve their senses or reflexes.

Dying Suns Subnet D6

Venit Lumen (D&D 5e Campaign Setting)

Venit Lumen

A thousand years after the Godswar, humanity is just beginning to claw its way out of the ashes. Ruins dot the world, strange fell beasts prowl the untamed wilderness, and the twisted descendants of elementals carve out empires.

It is a world teetering on the edge of darkness, fearful and superstitious. Thousands starve as greedy City-States hoard wealth. The gods, defeated and banished against their will by the Darkness during the Godswar have yet to make a reappearance.

The Crystal Sphere, a massive structure that has shed its light for millennia, has begun to darken, the four beams of light that connect the Power Crystals, its sources of pure elemental energy, flicker and wane.

Magic, once the lifeblood of the world, is faltering. Powerful spellcasters are dying or going mad. The magocracy of Teran Gard has vanished, replaced by a roiling sphere of azure fire.

The earth rots, fire burns out of control, along the coast; winds cease to blow, and fresh water becomes poison to humans and animals alike. The Crystal Sphere’s light dies, and the world dies with it.

         Paran: A City-State teeming with a hundred thousand citizens and the refugees of Damar. Allied with the Tengu of the north, and a constant enemy of the Sahuagin of the Inner Sea, Paran is one disaster away from vanishing into history.

Damar: This City-State was once a center of light, home of the Church of Healing, until the city was assailed and conquered by the Vampire Arcanist Kellar Janarth. Now the City lies in shadow, vampires and their spawn haunt the streets, and any living being that steps into the streets is hunted.

Galadiel: An emerald city, the home of the elves is beautiful to behold. Deep within an ancient forest, it inspires hopes and songs.

Malus: This City-State has enslaved by aboleth and other horrors that began showing up when the Crystal Sphere started to die. The people here have become… changed.

Crae: The City of Light. Beneath its joyous streets, bathed in crystalline light, are ancient ruins from an empire older than all of recorded history.

Curum: This City-State sits on the edge of the Ignas Wastes, bathed in the heat of the Fire Crystal. Obsidian buildings comprise this city, it is ruled by an Ifrit Sorcerer.

Giren: The Forest Kingdom. This kingdom is unique in the entire known world, as instead of a ruling council, it is led by a family of monarchs, descending from the First King, Gire.  It is a goodly realm, ruled by a fair hand, and guided by the Church of Light in all things.

Velus: This City-State is governed by a council of sages, those left over from the magocracy of Teran Gard. It is a city seeped in arcane might, with running water, plumbing, and automated defenses.

Terris: A City-State built into the Mountains, this majority Dwarven city is keeper of the Earth Crystal. The mines beneath Terris run deep, perhaps too deep, but the City-State’s wealth is astronomical.

Ibis: A Crystal flare decimated all life in this once prosperous city three years ago. The streets and buildings have melted, and shadows were burned onto their sides. Strange creatures roam the streets now, made of light and shadow.

Teran Gard: Once the seat of an empire based on arcane magic and philosophy, it vanished a decade ago, replaced by a sphere of azure fire. It was at this time that the plight with the Crystal Sphere was discovered. Whether or not these are related is unknown, but most people in the western City-States have begun to blame magic and its use for the current strife.

The Doom of Teran Gard:

Ten years ago, the magocracy of Teran Gard vanished, replaced by a sphere of roiling azure flame, this much is known. What is not known is the how or the why. Thirteen years ago, the Magelord Alisasta Demir began receiving visions from the Crystal Sphere, visions that foretold its doom, as well as the destruction of the magocracy itself.

She became obsessed with the visions, and a way to prevent these future events. Eventually, when there did not seem to be any way to stop the visions from coming true, she went to the ruling council, and a spell was devised to shift the city away from the material plane to another.

They failed. Instead of arriving in another material plane, they materialized onto the Plane of Shadow, where they were besieged by the shadowkin, malevolent beings that feed off of light and magic. Though the mages fought valiantly, it was a losing struggle. Due to the temporal differences between the two planes, they have been fighting six hundred years to keep their city alive. The planar fabric has changed the survivors, twisting them into beings much like the shadowkin. They aim to return to the material plane and conquer it, to drain the light from the Crystal Sphere, thus fulfilling Alisasta’s visions.

They are infiltrating the present time and leaching off of the Crystalline light, causing and hastening the death of the Crystal Sphere.

Thus was caused the doom of Teran Gard, and the doom of the Crystal Sphere and of the World.

Shadowkin: Beings immersed in the power of the Plane of Shadow, they develop traits of that dark place over generations.

Creating a Shadowkin Creature:

CR: Same as base creature +1
Alignment: Any (usually evil)
Ability Scores: The base creature gains a +2 profane bonus to Dexterity or Intelligence. (This begins to fade seven days outside of the Plane of the Shadow to a +1, and to a +0 after ten days outside of the Plane of Shadow)
Senses: As the base creature plus darkvision 60 feet and low-light vision
Defensive Abilities: A shadowkin gains damage reduction and resistance to cold and electricity based on its hit dice.
Hit Dice 1-4 Resistance: 5. DR: -
Hit Dice 5-10 Resistance: 10. DR: 5
Hit Dice 11+ Resistance: 15. DR: 10
Shadow Blend: In any illumination other than bright light, the shadowkin blends into the shadows giving it concealment (20% miss chance). A shadowkin can suspend or resume this ability as a free action
Shadow Affinity: A shadowkin that can also cast arcane spells is treated as casting a spell one spell slot higher when casting spells with the shadow descriptor.
Light Leach: As a standard action, the shadowkin can draw the light from a room of normal light to bright light into itself, decreasing the light from the room by one step, temporarily gaining 2d6 extra hit points that lasts a number of rounds equal to its hit dice. Also, as a standard action, it can release this light as a deadly beam that deals 2d6 fire damage. They can use this ability (in either form) three times per long rest.

Clerics/Divine Spellcasters:

Seeing as there are no gods left on this world, clerics are strictly domain-based. There are Churches, but they are worshipping ideals. The Church of Healing and the Church of Light both worship the Crystal Sphere.

Elemental Clerics (those worshipping Fire, Earth, Air, and Water) are numerous, especially in the areas near the Elemental Power Crystals.

The Crystal Sphere:

The Crystal Sphere is a sentient artifact that acts as the sun for this world. Millennia ago, it crashed into a dark world, dragging along the ancestors of the modern populace through rifts in the planar fabric. Its origins are unknown, but it is ancient and powerful. The gods were brought to the Crystal Sphere like moths to a flame, but so too was the darkness.

The Gods:

The Crystal Sphere brought with it gods of light and good. For centuries, they worked to bring their followers to the world. The world soon teemed with humans, halflings, gnomes, dragonborn, elves, and the like, bathing in the goodness and beauty that is the Crystal Sphere. This changed when the Darkness came. The Darkness in its hunger and its rage devoured the gods, and began corrupting their followers.

The Darkness:

Soon after the Crystal Sphere crashed into the world, shining its light through the skies, creating mountains and seas with its impact, the darkness formed and gained sentience, inhabiting the spaces of the world where the Crystal Sphere’s light did not shine. From it, hateful, twisted creatures were spawned. Terrors from dying suns were summoned. An empire of horror was created. The Crystal Sphere destroyed the heart of the Darkness, but its damage had been done. These creatures still exist, and their influence is vile. The City-State of Malus has been conquered by the descendants of this Darkness.