Briarwoods

The Briarwoods are Sylas Briarwood and Delilah Briarwood, a married couple originally hailing from the continent of Wildemount, specifically the region of Wynandir. They arrived as guests at Whitestone Castle several years before the events of Critical Role. They were responsible for the deaths of Whitestone's rulers, Frederick de Rolo and Johanna Klossowski, as well as most of the de Rolo children.

Origins
Though they were not nobles, the Briarwoods had some renown and enough powerful connections to maintain a comfortable life in the Dwendalian Empire. Delilah, specifically, was a lesser mage who had studied at the Alabaster Lyceum in Emon, indicating that she spent time in or might even have grown up in Tal'Dorei.

At some point, Sylas became sick with a disease that no one could seem to cure. Delilah, therefore, set out to find something or someone who could help her husband. Though she did succeed in this quest, she returned too late and found that Sylas had already passed.

Delilah was so distraught over Sylas' death that she began delving further into meditation and her magic, trying to find anything to save him. One day, she was screaming her frustration into the Astral Sea when a voice whispered back: "I can help you." Delilah didn't know it at the time, but the voice belonged to Vecna.

Delilah was given whispered directions in her dreams, which she followed blindly in her grief, and was eventually led to one of Vecna's old laboratories. There, on condition of her service to Vecna, she was given information about the Rites of Vampirism. Vecna helped her enact the rites on Sylas, using a fraction of his own power to bind Sylas to him and thereby ensure the couple's cooperation. It was in this way that Sylas became a vampire, and they both became servants of Vecna.

Flight from Wildemount
Necromancy, however, is outlawed in the Dwendalian Empire, and people had begun to take note of Delilah's activities. When Sylas' undead nature and Delilah's part in it were discovered, the couple were pursued and arrested. They managed to escape, fleeing to Port Damali on the Menagerie Coast with Dwendalian hunters in pursuit, bent on capturing them for execution.

In Port Damali, the Briarwoods encountered Dr. Anna Ripley, who was also fleeing the Dwendalian Empire for her own reasons. Since all three were fugitives from the Dwendalian Empire, they decided to work together.

Hearing about an isolated city called Whitestone, the new allies made it their next target. Styling themselves "Lord and Lady", the Briarwoods traveled to Whitestone Castle and were welcomed as guests of the de Rolo household. They began to make frequent trips from Port Damali to Whitestone, building a relationship with the ruling family there.

Takeover of Whitestone
The Briarwoods prepared their coup by making alliances in Whitestone and recruiting some people in the castle. Because the de Rolo family had intentionally isolated themselves from the rest of the political world, the Briarwoods had reason to think no one in the wider world would know or care if the de Rolos went missing or died.

During a feast that was held in their honor, the Briarwoods made their move. Their people suddenly and violently took control of the castle, killing or capturing anyone that opposed them. The de Rolo household was completely gutted, and only two members from the whole family survived: thirdborn Percival and his youngest sister, Cassandra. Percival, with his sister's aid, was able to flee, while Cassandra was shot with arrows during the flight and left at the mercy of the Briarwoods. It would later be discovered that she survived her injuries, only to raised as a ward of the Briarwoods.

The Briarwoods, once installed in Whitestone Castle, handed out titles to the followers who had helped them defeat the de Rolos. To maintain their iron rule over the people of Whitestone, as well as hide the secret of the de Rolo family murders and Sylas' vampirism, they ordered that communication with the rest of Tal'Dorei be cut off completely, isolating Whitestone and plunging it and its people into a era of hopelessness and hardship.

In the years following their ascension to power, they instructed that large portions of ground underneath Whitestone be excavated to reveal a Ziggurat that lay beneath the castle. They also worked with Anna Ripley to refine whitestone ore into residuum, using large acid vats beneath the city. This would later be revealed as part of a long and elaborate ritual for the benefit of Vecna.

Chapter 1
While Vox Machina were busy underneath Kraghammer, the Briarwoods were beginning to explore diplomatic ties with Sovereign Uriel Tal'Dorei III. They made a visit to Emon to state their interest in collaborating on the construction of a bridge near Whitestone across the Shearing Channel, a way of opening new trade between the continents of Tal'Dorei and Wildemount. They were able to convince the Tal'Dorei Council of their sincerity, fabricating a story that they had inherited Whitestone after the de Rolo family's demise.

When Vox Machina returned to Emon, the surviving de Rolo heir, Percival, happened to learn of the Briarwoods' communication with Sovereign Uriel. The mention of their names caught his interest, and he asked to be notified (discreetly) should they come back into town.

Chapter 2
During Vox Machina's absence in Vasselheim, the Briarwoods arranged an official visit to Emon to dine with the Tal'Dorei Council. By this point, Seeker Assum Emring already suspected that they were not entirely what they seemed.

Chapter 3
Vox Machina encountered the Briarwoods in person for the first time at the feast held to welcome them in Emon. After the feast, Vax'ildan attempted to sneak into their room and was caught, leading to a fight. The Briarwoods escaped and fled back to Whitestone while Vox Machina were forced to face the consequences of their actions in Emon.

While Seeker Assum left for Wildemount to look for possible dirt on the Briarwoods, Vox Machina headed directly to Whitestone. There, they found that the town had been completely enslaved, its people downtrodden, and the protective Sun Tree dead and defiled. Discovering a few stalwart allies of the de Rolo family—including Cassandra de Rolo, Percy's youngest sister, long thought dead by him—Vox Machina began to foment rebellion. They mounted attacks on the Briarwoods' allies, slowly crossing names off Percival's List, before infiltrating the castle itself.

After rescuing Cassandra and killing another of the Briarwood's allies in Professor Anders, Vox Machina pursued the couple underneath Whitestone Castle, where they feared the Briarwoods were preparing a dark ritual. The Briarwoods sprang a trap, nearly drowning the party in acid while they made off with a charmed Vax'ildan and with Cassandra, now revealed as a double agent.

While Vox Machina were struggling with the acid trap, Delilah and Sylas made their way deeper under Whitestone, to an ancient ziggurat that they had discovered and turned to their purposes. When Vox Machina caught up with them, Sylas was killed in the fray. Delilah, though distraught at her husband's death, pressed on to complete her long-awaited ritual. Though the ritual should not have been attempted until the day of Winter's Crest, still some days off, she was able to create a strange, hovering orb of destruction and anti-magic before Vox Machina could stop her. This was apparently not what she had expected from the ritual, though it was unclear whether she really knew what to expect at all.

Delilah was then caught by Vox Machina and killed in an act of revenge and penance by Cassandra herself, thus ending the Briarwoods' influence in Whitestone. In the aftermath of the Briarwoods' defeat, Percy and Cassandra reclaimed their home for the de Rolos, and those who remained of the Briarwood allies were either killed or converted.

Chapter 4, Chapter 5, Chapter 6, Chapter 7
With both Sylas and Delilah dead at Vox Machina's hands, their only influence on the story for a long time was in the form of the strange orb still hovering in the ziggurat below Whitestone. The orb, however, proved difficult to study, and little could be discerned of Delilah's intentions in constructing it. Eventually, breakthroughs from Allura Vysoren and Vex'ahlia led the party to conclude that the orb was a form of magical siphon into the Shadowfell.

Chapter 8
Over on the continent of Marquet, one Lionel Gayheart stumbled across a second ziggurat and orb being attended by cultists. He brought this information to Vox Machina, who had him bring them back to the place he had found. There, they came face-to-face with a resurrected Delilah Briarwood.

Delilah and her cultists fought Vox Machina before escaping through the second ziggurat orb, which now proved to be a portal when properly controlled. Vox Machina used this discovery to travel to the Shadowfell themselves. There, in the city of Thar Amphala, they witnessed Delilah's true endgame: the resurrection of Vecna. They met and fought Vecna himself, as well as Delilah and a Death Knight, atop the tower of Entropis in the center of the city. There, Delilah was killed a second time, this time by Percy.

The Briarwoods' story, however, was not yet over. Thanks to their help, Vecna was soon able to complete the rites to ascend to godhood. Vox Machina pursued him to the top of an undead Earth Titan. There, they were ambushed by Delilah, who had been resurrected again, along with a returned Sylas, riding atop an undead white dragon. Vox Machina were barely able to escape with their lives.

The next day, Vox Machina returned to the titan. On their way to confront Vecna, they were again found by the Briarwoods. This time, Delilah was killed—permanently, at last—by Vex'ahlia, while Sylas escaped in his vampiric mist form. After Vecna's defeat, Sylas was seen flying through the Vesper Timberlands outside Vasselheim.

Faction Members
The Briarwoods established and maintained control over Whitestone by earning loyalty and forcing obedience.
 * Sylas Briarwood: The Lord of House Briarwood and self-proclaimed Lord of Whitestone.
 * Delilah Briarwood: The Lady of House Briarwood and self-proclaimed Lady of Whitestone.
 * New Nobles: Subordinates upon whom the Briarwoods conferred titles, land, and power.
 * Countess Jazna Grebin
 * Sir Kerrion Stonefell
 * Count Tylieri
 * Duke Goran Vedmire
 * Undead minions: Sylas created vampires and vampire spawn, and Delilah created necromantic thralls.

Trivia

 * Taliesin had only told Matt that the Briarwoods came to Whitestone and murdered Percy's family. Percy didn't know anything else about them, so Taliesin didn't write anymore about them. Thus, the Briarwoods and their backstory were written by Matt.
 * The inspiration for the Briarwoods is from a ghost story Taliesin heard about in New Orleans. A rich married couple owned a house that caught fire. When the fire brigade went upstairs, they found disastrously mutilated bodies. It was a torture chamber where the people had obviously been kept alive while the mutilations were occurring. While the fire brigade was trying to figure out and process what they had found, the couple got into a coach with their surviving belongings and left the city. They were never seen or heard from again.
 * Due to their bond to Vecna and his cult, both Briarwoods have died and been brought back multiple times.  However, both of their final deaths were at the hands of Vex'ahlia.  Delilah was defeated and killed by her during Vecna's assault on Vasselheim and Sylas died later at Dalen's Closet, after attacking her and Percival on the eve of their planned wedding.