Sébastien grew up a very sweet child alongside his twin brother Jonathan, their father Joshua, and their very controlling mother, Francine. regardless, he loved his family, especially his ma... and oh boy, did she take advantage of this.
he would listen to whatever his ma told him, he was basically her puppet and emotional dumping grounds. Sébastien is very quick to latch onto people, and she made sure she was the only one who mattered in his life.
Francine
their biological father, Joshua Harley, was a private investigator and detective. Joshua tried very hard to get Sébastien away from Francine, but she would always pull him back. Joshua never got to helping the kids, because Francine convinced herself Joshua was cheating on her and hired a hit on him to have him buried when the kids were only ten.
later on during Jonathan and Sébastien's young adult years, Francine became involved with a shadow mafia by the name of La Populace and had previous relationships with their members. in fact, she dated a man by the name of Henri, who was an important figure among their ranks.
he cheated on her, and being the horrible person she was, she hired a hit on him and had him buried just like she did her previous husband. La Populace wasn't stupid. they knew it was Francine who ordered the hit and sent their own on her.
it was on a night with a full moon when the assassin came to their house and poor twenty year old Sébastien watched as he beheaded her with his katana in their living room. Jonathan hid, being the smart one. but Sébastien? he was covered in his mother's blood as he held her body and wailed the night away until the police came.
after that night, he was never the same.
Penumbra Covert
the two brothers had to get themselves together; their only parent was dead and they had to move on. Sébastien and Jonathan founded their own private investigation agency together, Penumbra Covert, using their biological father's old office. the two promised that they would get to the bottom of La Populace together. Sébastien for the sake of their mother, and Jonathan for the sake of Sébastien.
in reality, Jonathan knew that Francine was awful and it never sat right how she treated Sébastien, but all he wanted was closure for his twin brother. he would do anything if it meant Sébastien would find peace and move on.
Sébastien began taking some very sketchy requests behind Jonathan's back, being moved by the clients' stories of their affairs and dismays, as though he'd seen himself in them. he would blackmail cheaters and mistresses to literal death for the sake of revenge, not being different from what his mother was.
Jonathan confronted Sébastien and it resulted in a fight between the two twins. Jonathan revealed that Francine was the one who sent the hit on their father, Joshua, which Sébastien did not take well at all.
Sébastien walked away from that conflict and it was the last time Jonathan ever saw him for years. when Jonathan returned to the office and checked their home, Sébastien was nowhere to be seen. he'd taken nearly everything he deemed he owned and went his own way.
Lunar Church
after the fight the two brothers had, Sébastien headed to the Lunar Church. if he wanted change, he'd do it within the system. he tried very hard to forget about Jonathan, with questionable results.
during this time, he stayed with his friends, Selena and Helena. both looked up to him since their childhood and were eager to help him in his plight. he spent nearly six years working up the ranks, pulling strings and using his abilities in informational warfare to knock out competitors with their help. this man knew what he was doing, and soon enough he became Archbishop of the Church and she became his advisor. Helena became sergeant major of their army.
and what did he do with this newfound power? pull even more strings with his position to pass a law that stated that all who practiced shadow magic must be punished by death out of sheer rage. no one would be hurt by the Acolytes ever again. it took away his mother and his family, he'll put a stop to it.
eventually, he did take down La Populace, indirectly with Tes' help. Sébastien never forgot about Tes even during the years they were apart.
Jonathan (or rather now, "Tes"), was practicing shadow magic at the time. Sébastien knew this and a secondary purpose of passing that law was to draw Tes out of hiding and punish him for not being there for him when he needed it. he knew Tes was too smart to let himself get killed by some dumb cops.
oh, and he made gay marriage legal and abolished arranged marriage. that's about the only good thing he did as Archbishop. Desmond, his childhood best friend, was very happy about that.
The Finale
eventually Sébastien snapped, his unhinged wrath reaching a breaking point. the only person who could convince him to step down was his brother, but unfortunately Tes was extremely hesistant and violently so.
it's a long, winded story, but the climax ended with Sébastien metaphorically tearing off the skin of the Moon and wearing it, trying to play god. it says something when Sébastien is literally so powerful that his mind overpowered a thing that is supposedly a deity.
Desmond had to convince Tes to face his younger twin, nearly getting killed in the process by an enraged Tes in his shadow form. Desmond, who also had a younger twin who he dearly loved, told Tes that he understood what it was like, and it wasn't just Sébastien's life at stake, but the entire world. Tes would soon come back after a cigarette to help talk down Sébastien from his power trip.
if it weren't for Tes, the mob would've had Sébastien's head on a pike. can you blame them after all he'd done? but Tes wouldn't let that happen. he disappeared with a heavily wounded Sébastien into the darkness, and that was the last time the general public has ever seen the Archbishop.
SUB PLOT: Adrien Pierre
Francine, his mother, got him a job as a secretary to her fifty year old friend, Adrien (who was also the Pierre quad's father). Adrien sexually assaulted him, forcing him to basically pretend to be a girl because he wanted a pretty lady as his assistant... otherwise, he would blackmail his mother if he'd let anything out. Sébastien couldn't let that happen.
so he played along, wearing a skirt, heels, and lipstick. he would then learn how to moan like a lady in bed, because that's what this sick pervert wanted. he would do anything if it meant keeping his mother safe.
but Sébastien was never a submissive person in the first place. he'd purposely speak masculine, remind Adrien very firmly that he was a man whenever they got it on, and adopt male mannerisms. it wasn't enough, so Sébastien began to return fire and blackmailed Adrien.
that was the moment when Sébastien realized he had the power to bury people with just words, and boy did he use them from then on.
the most fucked up part? is that Francine didn't care that Sébastien began wearing women's apparel more often all of a sudden. she always wanted a daughter.