Seline's History
Early History
Before 750 B.C, she was banished from her village to an isolated island as a punishment for her psychic abilities. Initially, she inhabited the island alone, until another village girl with the same abilities washed upon the shore, Sybil.
Later on, thanks to their shared gifts as psychics, they grew close, like sisters, related in everything but blood. Unknowingly, she managed to explore her powers and improve them to fulfill the deed of luring the sailors' ships to land upon the island she inhabited. Those sailors were from the very village that previously banished her and hence according to her, they deserved to be punished. She'd brutally kill them and along with Sybil, who had no clue about Seline's actions, they would eat their flesh, becoming cannibals.
Years later, the truth was revealed and Sybil learned about the vile deeds her adoptive sister had been doing all along - dragging her along without knowing anything about it. Consequently, the latter sought to cleanse her soul from the filth that stained it and thus tried to commit suicide by jumping off the cliff.
However, Seline found out what her sister had done and before the former met her end, she prayed to God for help, though another came. A strange man suddenly came out of nowhere, claiming to be Arcadius' spirit. The terms of the deal were that he would save her sister and make them both immortal, beautiful and eternally young, but in return, they would feed upon flesh and offer him the souls of the wicked. Seline accepted the deal and they were both turned into the Sirens, servants of Arcadius.
1790
Seline, along with Sybil, came to Mystic Falls searching for souls for Arcadius, though the witches caught their eye. While there, they befriended Ethan Maxwell, the local metalsmith and learned of the witches spelling a metal work of his, the town bell. She sirens Ethan to add the Staff of Arcadius to the bell which corrupted the witches' magic and instructed Ethan to ring it twelve times to unleash hellfire.
The witches stand together and protect the town from burning, though at the cost of their lives. Before they are able to take the bell, they are lured through the tunnels underneath Mystic Falls to the Armory's vault by Ethan and Beatrice Bennett. They are trapped in the vault with magic and along with Ethan who starved to death in the secret room. At the same time, the Armory received a shipment from Mystic Falls that included the ancient Tuning Fork. Once trapped, Seline was held captive there with Sybil for almost a century.
1882-1883
When Dalton St. John opened the Armory's vault, Sybil took control of him and caused chaos as she took away his humanity. Given this opportunity, Seline took her chance and was able to escape, leaving her sister behind in the process. A year after her escape, Dalton records that Seline returned to Mystic Falls; she searched for the bell, though she would not find it.
1917
Seline was in Monterey where she saw a ripper named Stefan Salvatore. She was planning on killing him (and sending him to Arcadius) though when she looked into his mind, she saw a good person who was turned into a monster. Seline erased Stefan's memories of that moment and left.
Becoming a Nanny
Months after her sister was released from the Armory's Vault, Seline became the nanny of Josie and Lizzie Saltzman, having found out about their siphon nature. In the process, she started spying on the Mystic Falls Gang after her sister got free with Damon and Enzo's forced servitude.
Throughout TVD Series[h]
[h]Season 8
In Hello, Brother, Seline is introduced as Josie and Lizzie's nanny, with Caroline telling Stefan how she suspects Alaric has the hots for her. Alaric also seems to be impressed on how she did everything so effortlessly on Caroline's To Do List. Jokingly, Alaric asks if she's a doppelgänger, which seemingly makes her confused but he brushes off the question.
Later, Seline drops off the girls to spend lunch with Caroline at the News Station. While there, Pete, from Sound, gave her a flash drive to give to Caroline. With the girls spend time with their mother, Seline leaves to grab a salad.
Later that night, Seline calls Caroline asking if she's heard from Alaric, that his phone has been going straight to voice mail. While on the phone, she hears the front door open and assumes it to be Alaric but Caroline reassures her that he's still working the tunnels at the Armory. Seline asks Caroline if she thinks the girls would leave the house, as the front door is standing wide open. She shuts the door, but upon returning to the kitchen, the knife she was using is missing. She tells Caroline that someone is in the house, but before she say anything further, Virginia sneaks up behind her, slitting her throat. Seline falls to the floor, seemingly dead.
Caroline rushes home and seemingly saves Seline, feeding her some of her vampire blood to heal her wounds. Once she's taken down Virginia, Caroline "compels" Seline to take the girls to dinner and for ice cream, to be gone for a couple hours so she can interrogate Virginia for her attack. Seline does as she's told, mentioning that they will get hot fudge sundaes.
In Today Will Be Different, Seline asks Alaric to sign permission slips so Lizzie and Josie could go on a history field trip. She then questions Alaric as to why she was overpaid, but Alaric revealed that he and Caroline decided to give her a raise, secretly as payment for risking her life to protect their children.
Later, Seline and Alaric converse after he arrives home late. Playing ignorant to his research, Seline jokes that Alaric knows where Georgie's secret tatoo is and says she will see him the next morning.
In An Eternity of Misery, Seline's story was told by Sybil. She was an island girl who was banished to the island for having psychic abilities. One day, Sybil arrived on the island and Seline became her sister. She killed sailors, fed on them and forced her sister to feed on them too. When Sybil tried to kill herself she made a deal with Arcadius and became a siren. Georgie was caught by Seline when she broke into Alaric's house and Seline started controlling her. Later it's revealed that she sent Georgie to lock up Alaric and free Sybil. When Georgie failed to do the latter, Seline killed her and fed on her dead body.
In Coming Home Was a Mistake, Seline heard about Tyler's death and checked in on Alaric to see how he was doing. She tells him that she lost her entire family expect for her sister, adding in the fact they're estranged. She gets him to agree to have her escort the girls to the Carnival where they win a dead goldfish. Seline then starts to groom them to be servants for Cade. She then takes them, knowing that her identity has now been outed.
In Detoured On Some Random Backwoods Path to Hell, an Amber Alert is out for the girls and Seline is listed as their kidnapper. Seline is surprised to see Sybil and Damon walk into the Oakwood Diner, where Seline had taken the kidnapped twins, Lizzie and Josie. As her sister joins her, Sybil makes it clear that she still holds hostility for her sister after she left her to rot in the Armory. With the twins, Sybil deduces Seline's plan to offer them to Arcadius in exchange for their freedom. After everyone at the diner notices them the Sister and Damon sets off, eventually coming to White Cedar Motel clocking the twins with their magic where they rack up a body count as an offering for Arcadius. Once he appears to his servants Seline makes her plea to offer up the twins in exchange for their freedom. The twins intrigue Arcadius, though before it can be accepted, Sybil offers up a better offer, two immortal vampires: the Salvatore Brothers. Later that night Sybil reveals that she cut Seline out of her deal with Arcadius and that Seline did not have a free pass out of hell.
In The Next Time I Hurt Somebody, It Could Be You, Seline was seen in a house, where she "sirened" the minds of its residents (Tammy) to accept her, and spent the Christmas with them. Bonnie and Enzo showed up and she talked to them about her story with Stefan. Bonnie helped Seline, by calling Alaric, and she told him that she needed to erase the psychic imprint that she created, otherwise they would be forever linked to her. After hearing her out, she then gave Bonnie and Enzo the tuning fork and they left. Later Seline met with Alaric and the twins, where she erased the girl's memories of her, breaking the link.
In We Have History Together, Seline does not appear yet leaves a note for Sybil to find: "Hey, sissy. Looking for something? - Seline." Caroline finds out the reason behind for Seline cleaning and reorganizing her garage: to find the Mystic Falls antique church bell that was in Elizabeth Forbes' possession. Sometime since becoming the twins' nanny, she had found and taken the bell, much to Sybil's dismay.
In The Simple Intimacy of the Near Touch, Seline informs Caroline that she has the biggest piece of the artifact that could kill Sybil, who was out of control, however Caroline along with Bonnie dismiss Seline and her offer to be allies. She informs Dorian that Matt is only one capable of ringing the real Town Bell because of his family's bloodline.
In Nostalgia's a Bitch, Seline conspires with Stefan to destroy Mystic Falls, for all the souls that Arcadius wants while killing Sybil. Ultimately, Seline's plan to sacrifice the town in exchange for Sybil's death is thwarted and they meet up a a dinner and Sybil wants to attempt to bury the hatchet between her and Seline. Sybil reasons that if Damon and Stefan could, then so could they. Seline wanted an apology for Sybil screwing her out of the deal she made with Arcadius, though Sybil refused, countering with that she turned her into a cannibal, sold her into servitude and abandoned her for over a century. However, before the conversation concluded they were interrupted with the appearance of Arcadius himself. Seline attempts to plea with Arcadius, but he refuses them, telling them that he will handle the Salvatore brothers and Mystic Falls from now own and proceeds to kill them both with hellfire.
In What Are You?, Matt Donovan relives some of his ancestor's moment from 1917, where Seline and Sybil had came to Mystic Falls in an attempt to destroy the town via hellfire. With their plan foiled, they attempted to have Ethan Maxwell to use the Maxwell bell to free their master from Hell.
