The Eye of Night
The druid nods in response to Weylan's question and begins to explain "In an earlier age of the world, a warband of the wood giants overcame the green dragon Estaraloth. One of the heroes of that band brought a great gem from the dragon's hoard, a large smooth topaz the size of a closed fist, and presented it to their tribe's druid Aran Hieuli as thanks for the healing that had saved him from the ravages of disease as a youth. The druid could tell that it held potent focusing magics but he knew not its purpose and brought it to his Circle for further examination. A hag among the circle, Ventrelle Cadori, was known for her powers of divination and she discerned that the gem was a summoning focus, tied to astromancy and fell realms beyond the stars. It could not be used alone, but combined with the proper other tools a skilled master could use it to draw on various other realms and powers, binding alien energies and fell beings to his will. Depending on the sacrifices performed and the current alignment of heavens at the time it was used different celestial alignments would provide access to different realms, many of them powerful and inimical to all life as we know it. Uncontrolled, such beings could be dangerous individual hazards, while some of the energies could potentially warp or scour all life from Wildwood entirely. Cadori named the gem the Eye of Night.
"The Circle decided the artefact was too dangeous and should be destroyed, but it proved resistant to shattering, lightning strikes, dragon acid, cursing, magical destruction and numerous other methods that were attempted. Cadori determined that it could be destroyed but the specific method was unknown and might require the direct power of a divinity. The Circle therefore decided to safeguard the Eye of Night, lest it fall into the hands of one who might unwittingly unleash disaster upon the Wildwood as they sought to bind personal power to themselves. Knowledge of the Eye of Night was kept a closely guarded secret of the Circle, lest those who lusted after power at any cost would not be tempted to seek it out.
"A fey realm was established, this realm, that was cut off from the vibrant full realm of Wildwood. It required a connection to the Land and could be brought into conjunction by those with a connection into or out of the realm. I was a member of the Circle and volunteered to undergrow the Evergreen Transformation ritual sacrificing much of my druidic power and my old life to become the Bloodthorne Guardian, bound to this realm for ages to come. Once I had done so I accepted the Eye of Night, hid it within my very being, and took up the stewardship of this realm, establishing further wards and defenses should its primary one ever be pierced. As the Bloodthorne Guardian I hold dominion over this fey realm and the natural features and wildlife native to the realm. Over the ages I have maintained contact with the Circle, acting as a teacher for many druids who have come to me to learn, while only the highest members of the Circle, such as your druid Zallon, held the true secret of my guardianship should disaster ever fall and I needed outside help.
"And disaster has fallen with these invaders."