Transmigrated as a Villainess Caught in a Love-hate Web

Hardworking corporate drone Nina Donovan transmigrates into a book one day, forcibly bound to a "Villainess System" that demands she bully the male lead, threaten the male lead, and take her arrogance, dominance, and lawlessness to the very end. Once the corrupted male lead retaliates, causing The Donovan Family's bankruptcy and her own gruesome death, she will be rewarded with ten billion and returned to her original world. Of the long list of tasks, Nina Donovan only remembered these words: Ten Billion! Excellent! Her impoverished self was finally saved. Eagerly responding to the mission, Nina Donovan carries her villainy to the very end. Her own younger brother, who has been tormented by her for years, falls in love with the female lead due to his lovesick personality. Nina Donovan immediately assigns him ten sets of exam papers. "Don't you have any self-awareness about your shitty grades? You're not allowed to love until you've finished them! Are you even worthy?!" The second male lead, her childhood friend, is madly obsessed with the female lead and treats her love like trash. Nina Donovan immediately sheds this love-struck fool persona. "We're done! We must be done!" But after cutting ties, why does he come back begging for forgiveness? She kicks him away directly, her principle being: "My love is precious. You're a scumbag, you're not worthy." The original female lead, with a full stack of good-luck buffs, never backs down in the face of power. Nina Donovan applauds wildly. "Excellent, excellent!" She immediately finds an opportunity to cut off her financial aid. The female lead ends up on the streets, only wanting to go back. "No money left, huh? That's sure to make you behave!" And the male lead, whom she mercilessly tormented and who hated her to the bone, swears to her with bloodshot eyes: "Nina Donovan, you'd better not fall from grace. If you fall into my hands, I'll make sure you die tragically." Later, The Donovan Family goes bankrupt. Having completed all the plot points, Nina Donovan is forcibly taken "offline," and true to the male lead's words, she dies miserably. But could someone please tell her why, after her death, her brother who hated her, her childhood friend who saw her as trash, and even the male lead who wished he could strangle her, are all on their knees begging for her to return?