The Blackwood lineage is the last of the Ancient Bloodlines to survive to modern times. There once were four primary families of witches that possessed the oldest and most powerful magic - Avalon, Blackwood, Cromwell, and Westgrove - until all but the Blackwood were snuffed out of existence in their attempts to avoid pursuit.

Before the extinction of the majority of the oldest magical bloodlines came to be, an ancient prophecy had warned of the arrival of a "darkened child". According to the prophecy, this child would be the product of a Fallen One (demon) and a daughter of one of the Ancient Bloodlines, and would bring death to all witches and damnation to all Man.

Families Avalon, Cromwell, and Westgrove resorted to extreme measures that ultimately led to their own extinction, methods including magically-induced sterilization of the blood-born females of their lines, and even murder of newborn female children. All of this, in an effort to evade fulfillment of the prophecy. Due to these actions the succession of their bloodlines relied solely on the males to carry on, which greatly diluted the power of their magic and decreased their numbers significantly over time, until the last of them were extinguished even before the dawn of The New World.

The Blackwood, however, sought a different path. They receded into hiding, taking another family name and greatly confining the use of their magics. Natural abilities (those which each witch is born with, though most only excel in one) were bound for both males and females of their lineage until maturation, and ritual ceremonies were reserved only for holy days and performed in secret. This method only had a short-term period of success, however, which was compromised when the last of the other Ancient Bloodlines was wiped from existence. With the Blackwood the last family of the Ancients they would soon discover they had become targets for the demonkin they had sought to elude. This threat proved costly, when in the late 17th century a Blackwood witch by the name of Amelia was seduced and impregnated by a Fallen One, Azazel. Sadly, Amelia sacrificed herself with the unborn child in an attempt to terminate her pregnancy via magical methods.

Realizing they would now be stalked by this demon, both for revenge in thwarting Its plans as well as Its attempts to try again, the remaining family decided to relocate to The New World. Unfortunately, The New World brought with it a new set of problems in the form of witch hunts and trials. The Blackwood family remained under concealment for the majority duration of the trials until a secret faction of extremist humans, calling themselves Hunters of the Right Hand Order, took it upon themselves to investigate and slaughter suspected witches. When Josiah Blackwood stood out against the unjust murders of humans who did not even practice magic he unintentionally drew attention to himself and his family. As members of the Order pried into the past of the family and spied upon them they soon uncovered the truth, as well as old texts referring to the prophecy. When the Blackwood were set upon by the Order they once more had to flee to survive.

For centuries the Blackwood family has been moving, hiding, remaining in secret until either the demon or members of the still-existent Order managed to track them down, only to flee once again. Since no generation of the family has stayed in any one place long enough to take root and the ever-present threat of the Order looms to whittle away at their numbers, they arrived unto the 21st century with only a handful of blood relatives remaining. Currently, last known blood of the Blackwood line is Joel Blackwood, a man well into his fifties and married to a human woman named Beverly. They reside in Toronto, and because Joel has vowed since his younger sister's death to never again use his magic they've been successfully avoiding the eye of the Order for over twenty years. His wife is also barren, and Joel has solemnly come to grips with being the last of his bloodline to ever know the Ancient magic.

Or so he had planned...

Eden Cassidy lived a charmed life, raised by loving parents in a picturesque suburb of Rochester, New York. Her happy life is threatened, however, when she begins exhibiting strange abilities alongside the onset of puberty that only become greater and harder to control into adulthood. Unbeknownst to her, she is the last remaining female of the Blackwood line of witches. She was born to Regina Blackwood, who was murdered by Hunters of the Order after her birth. Her last remaining blood relatives, her Aunt Beverly and Uncle Joel, then secreted her away to an orphanage. In hopes for a better future and greater chance of survival for her, they placed her up for closed adoption, thinking she would not be hunted as a Blackwood if no ties between them could be found.

Eden managed to live a happy, simple life up until the development of her abilities. Though she attempted to hide them from her parents they soon discovered what she could do. It was then, to her surprise, they didn't shun her but rather confessed to her that she was adopted. With their support she managed to establish some wavering control over her powers that seemed to grow harder to contain with each passing year. Finally, she completes her college degree program and with the assistance of a tech-savvy friend and classmate manages to finally track down her last remaining blood relatives in Toronto. On a journey for the first time completely by herself in a completely unfamiliar city she sets out to find out who she truly is and, hopefully, how to establish control over the increasingly haywire behavior of her abilities. [This is where our story begins.]

NOTES:
Hunters of the Right Hand Order: Religious "knights" who hunt and kill witches. They are a worldwide organization, not sanctioned by any church, fanatical and ruthless. Though they target all witches they have a distinct fixation on the Blackwood bloodline, always searching for them to snuff them out and avoid the prophecy that heralds the damnation of humanity.

Azazel/Asmodeus: I'm combining these two demons from lore to better fit the story (mainly because Asmodeus has the hierarchical rank I had in mind, but Azazel better fits the bill for fathering a "Doomsday child"). Asmodeus is described as "a Prince of the Seraphim, burning with desire to tempt men into wantonness" a.k.a. Lust, while Azazel is credited with "teaching women the art of deception and witchcraft", is said to have taught heavenly secrets to Man that lead humankind to sin, as well as being leader of the Watchers (a lower caste of fallen angels). Azazel can either be appointed to this task of seducing a Blackwood witch by those he answers to or can choose to fulfill this task to garner favor/power. References Here, Here, and Here

Magic: Rituals are formal events that often require multiple witches to undertake, especially for large-scale tasks (like casting protection over a large object like a plot of land or a house). Though Covens are not uncommon they are unsafe with the likes of the Order traipsing about. Each witch is born with a specific ability (some develop mental powers, others have abilities linked to the elements). Witches of Ancient bloodlines, which no one thinks exist anymore, are masters of multiple abilities born from ancestral magic. Witches are born from a bloodline with magic in their blood, a human cannot practice magic they are not born with.

The Aether: The void between the Underside and the Earthly planes. Demons often use it as a pathway to traverse across planes, as well as across long distances within the same plane (example: from Toronto to Italy). It is accessible to some witches, on a very limited scale, and usually only those with astral abilities.