Aíysfaer Crystal (eye-iss-fare)

These beautiful arcane tools that write runes and glyphs with light look like nothing more than a refined piece of euhedral crystal. However, this is no mere mineral... it is lost, chaotic energy given a new form having been placed there by a goddess before she left the mortal realm.

Or So the Story Goes...

In the wake of the Brink, as the world started to reshape and the skies began to clear, the deities that remained realized that there was much more they had saved from the Void. Boundless energy, the essences of fallen worlds that had been hoarded for consumption had been released and while the deities could not recreate the destroyed worlds, they could make something new. So, each one took the energies that best served them to create something on what was left in Creation.
It is said that the goddess Valkeryth gathered the most unpredictable and chaotic of energies and took them into the heart of an abandoned, hallowed mountain that had once served as a fortress and haven for warriors of the past couple of centuries. The energy, despite its nature, took root and a form, solidifying in the mortal realm as crystals and taking shape on almost every surface it could, only just leaving a path that could be traveled for all.

The Song of Yluinar

When you are ready, you will hear it. A song meant just for you.

— Cinta Valin

While the mountains are known as many things and the entrance to this cave will forever be argued by all save for those from Darcanis, it is an agreed upon truth amongst all that it is a song that will lead you to navigate the seemingly endless labyrinth of crystal.
A traveler venturing into the cave seeking a crystal for their own use can only seek out one crystal and will only ever hear one song. Should the crystal ever be lost (away from contact for a week) or destroyed, the crystal will become dust and a new one will need to be retrieved from within the cave as the "song was returned".

Aíysfaer Crystal

Once found and taken from its place, the once colorless crystals changes and can take on many different colors and in rare instances, can even change its shape somewhat. An aíysfaer crystal whose bonded's soul has been drastically changed will be fractured and, when used, the light which serves as a display of the channeling rygyra can be seen visibly flickering. Once a crystal settles on a color which is said to reflect the soul of a person, the color can only change if something alters the person wholly.
As this is a place of balance, there are places to get crystals for dark deeds. However, only the disciplined can reach here, for if a destructive force were to come near with the intent of destruction in order to keep what they have, the crystals would defend themselves and tear its energies would tear the being apart and take its energy to create even more crystals.

The Secrets of Darcanis

The "Light Write Crystal"

Crudely referred to as such by the neighboring areas, the aíysfaer crystals are seen when mages use them to perform rituals or cast spells.
Instead of using a surface, the caster may write in the air and the light that is seen as a caster writes is in fact the energies of the person made visible through the crystal. Like any other writing tool, the crystal allows the writer to see what is being written. However, once finished, the writing will disappear leaving no visible trace of magic behind. When writing with intent on a surface, similarly, the markings will stay during spellcasting if it is meant to but will otherwise disappear if the spell is used or the caster dismisses it.
While the tool typically leaves no writing, it does leave faint traces of magic and it can be used in magework such as inscribing, spell crafting, and/or rune-smithing as an arcane focus and tools are needed. Only in these latter instances will the writings from the crystal remain with the light taking permanent form where it is needed no matter what surface is being used.