Isekai'd as a side character

Sasha, the daughter of a poor noble family, approaches noble ladies with her innocent appearance and cold wit. Hence, she got the nickname “the Nobles’ Pet”, Rebecca, the villainess of the original work and the prince’s fiancée, appears in front of Sasha, who’s using her talent to live the sweet life. Knowing the end of the original, Sasha tried to stay away from Rebecca, but she cannot take her eyes off her cool and collected demeanor.
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Ertha was reincarnated into a rated 19+ male-oriented fantasy novel.
As the original story goes, Ertha was eaten alive by the protagonist Zahid, but I can’t die like that.
I offered a deal to the main character who’d eat me up. I’m the target of the proposal, 5 billion Marukas. All I have to do now is run away before the main character gets a chance to eat me.
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○ : cannibalism mention; hanging; murder

Poisoned to death by her own betrothed? Eunha didn’t wake up in a novel’s story just to get killed off again as an extra. To change her story she needs a cover—six months pretending to be the fake fiancée of the novel’s male lead. But will this demon of a man help her avoid another ill-fated ending?
○ (unsure if she shows up or if dies pre-story)
○ : violence; kidnapping
○ Rec, I guess, but tbh I dropped it cuz a plot twist was spoiled and

I tried to save the sub male lead, who was poisoned by the female lead, but an accident happened! He said he would repay the favor, but he randomly sent me to the most notorious villain, the Family of Assassins. Will I be safe in this villainous family throughout my three year contract?
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○ : child abuse (shown briefly)

I woke up one day inside the story of a novel as the maid of the disgraced duke and side character, Alejandro Quillo Vel Laviti. Will Alejandro’s fate change with the appearance of a new character? What is the truth behind his cursed mark?
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○ : child neglect
○ Older than he looks; due to malnutrition and curse?
○ I was hesitant to add due to long term pre-story, but since it’s long I’ll allow it; becomes present somewhere in the 20s or 30s

After I finished my SATs I was reading a novel about the pitiful Ludia who had no partner. The friend of the stalker villainess, who gets her executed. The pushover who followed her friend that brought her doom, also known as Extra 1. Why do I remember an extra who’s of no importance?
Damn it, I became that Ludia! I made up my mind that I won’t die miserably and will live on.
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○ Promo

When she opened her eyes while cooking ramen, she woke up as the maid of the queen who was treated coldly by the king in a BL novel in which the king, concubine, knight, servant, and librarian were all gay.
Will she be able to survive safely after becoming an ordinary maid?
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○ : infidelity (though an arranged marriage); abusive relationship (that’s the only way to describe how the king treats the queen); child taken from mother; possibly rape

I became a side character who was the younger sister of the male lead in a martial arts novel. Not only that, but I was sold off to the demonic cult for my family’s sake where I met the young master, Hyuk Dojin.
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○ Her importance is kinda unclear; I mean, I’d have to actually read the “novel” to know. I’m just gonna guess that she’s not a main character.