Simone Doffler's History
Slayer Organization
Thanks to Buffy Summers' plan to defeat the First Evil in 2003, Simone Doffler was one of thousands of Potentials to be activated as a Slayer by Willow Rosenberg's spell. Simone was soon located and recruited into Buffy's Slayer Organization, where she was a member of Rona's training squad based in Chicago. Despite her strength and talent in battle, Simone wasn't particularly well-liked among her peers, one of whom observed that she would be unwilling to risk her life for others. Eventually, Rona transferred Simone to Andrew Wells' squad in Rome, believing that a less urban setting might soften her "rough edges"; however, Buffy later described this as Rona "passing the buck" onto Andrew.
Simone continually expressed a desire to use firearms instead of traditional Slayer weapons. Andrew dismissed her for even suggesting this, insisting that Slayers did not use guns. Later on, Simone met three like-minded Slayers and finally went rogue. Alongside them, she broke into a weapons storage facility and stole a cache of firearms, including machine guns and ammo. The Slayer Organization attempted to track her, but she had gone off the grid.
Going rogue
Buffy and Andrew joined forces to track down Simone who had amassed a full-sized squad of her own, with whom she had taken over an entire island near Milan and expelled its original inhabitants from the island's town. She rescued her subordinate, Nisha from a trap set by Andrew and escaped with a massive Ragna Demon bred by Andrew, intending to use it as a weapon.
Like Simone expected, Buffy went to the island to confront her. Once the two met inside Simone's seat of power, the town's opera house, she offered Buffy the Ragna Demon (which she nicknamed "Arachnophobia") in exchange for Andrew, whom Simone had grown to hate while he had been her Watcher. Buffy, however, refused to leave without Andrew even if she recuperated the demon.
Simone refused to let Andrew go and reminded Buffy that she was outnumbered sixteen to one. However, at that moment, the Italy Squad showed up to rescue their Watcher. The Squad refused to fight against Simone and her followers in fear they might employ their firearms against them and chose to leave to fight another day. Uneasy with leaving the island to Simone, Buffy released the Ragna Demon so she would do some damage to Simone's operation.
Simone's criminal activities were only part of the various events which helped usher in a new pro-vampire, anti-Slayer world order; together with the machinations of the Twilight Group, the new Harmony Bites reality show hosted by the vampire Harmony Kendall, and the destruction of Sunnydale, the Scooby Gang and the Slayer Organization were forced into hiding as the world now viewed them as dangerous terrorists.
End of magic
Following the destruction of the Seed of Wonder and the subsequent end of magic, Simone infiltrated a United States military facility and murdered the General that had aided the Twilight Group and provided a large number of U.S. Army soldiers to battle the Slayer Organization.
Some time later, Simone made her way to San Francisco, driving a VW van full of weapons claiming that she was about to do something that would remind the world that the Slayers still exist. Eventually, Simone recruited Severin, a vampire hunter with the power to drain the powers of mystical beings, and sent him out to drain Buffy's powers so that Simone could kill her. Though he nearly succeeded in doing so, Severin was stopped by SFPD detective Robert Dowling and shot. While he was recuperating in the hospital, Simone approached him, angry that he failed. Simone refused Severin's subsequent request to drain some of her powers to heal himself, telling him that, with his failure, she will need to be at full power to kill Buffy.
Unknown to Simone, Andrew built a mechanical body of Buffy and carefully transferred the true Buffy and the robot Buffy's consciousness into each other's bodies. Simone kidnapped the real Buffy's body from her house, believing that Buffy's body contained Buffy's consciousness; however, she soon became suspicious because of the difference in Buffy's personality and her poor fighting ability. Buffy, Spike, and Andrew managed to tracked down Buffy's true body, and Simone was forced to fight Spike and his crew of bugs, killing many of them in the process; she managed to escape and Andrew eventually returned Buffy's consciousness to her human body.
Deeper Well
Later, Simone came up with a new plan: to feed Slayers to zompires, hoping to find a way to keep their minds intact so she could become one and fight Buffy. She and Severin met Xander Harris and they learned that Dawn Summers was dying. They offered to help stop this by going back in time to avert the Twilight crisis, and enlisted him in stealing information from Buffy's Vampyr book, which he agreed to. The information in Vampyr led Buffy, Willow, and Xander to the Deeper Well in England, where they hoped to find enough magic to save Dawn's life. Meanwhile, Simone and Severin entered the Well's New Zealand entrance. Inside, Simone awakened an Old One, Maloker, who had sired the first vampire in legend. Becoming a Slaypire herself, she directly confronted Buffy with her improved powers and abilities as Buffy's other allies battled the Old One itself.
Simone and Buffy were locked in fierce battle. Simone revealed to her that she was not a zompire since she had been transformed by an Old One whose blood was stronger than average. She also expressed her hatred of Buffy, telling that she had never wanted to be a Slayer but had to because of the Slayer Organization. As the battle raged on, Simone proved to be far superior to Buffy's abilities despite her efforts, and particularly enraged Xander when she revealed that she never actually intended to help save Dawn at all. Getting distracted by Xander being in danger, Simone overpowered Buffy entirely. Stabbing her deeply in the shoulder with her own weapon, Simone rendered Buffy unconscious and lifted her with the scythe. Holding her like a trophy, she taunted the others and declared she had won. As she prepared to leave the well, she left Buffy to be finished off by Maloker, only for him to be slain by a magical burst from the new Seed of Wonder spawned from Willow's magic.
As Buffy and her friends attempted to escape, Simone, single-mindedly determined to kill Buffy, tackled her from above and dragged her back down. Simone initially had the advantage and nearly beheaded Buffy with the Scythe, but only succeeded in cutting off some of her hair. Getting the upper hand in the fight, Buffy told Simone that she regretted ever having made a girl like her a Slayer, before using the Scythe to stake her.
