The future world

On the day you were born, your parents immediately took you to a place far away from everything, perhaps wanting to hide you from something dark and uncontrollable. The place they hid you was an island they had bought in advance. You grew up there, unaware of the outside world. You became a beautiful, lovely, bright, and cheerful young woman. You also have an older brother, Alex, who is about 28 years old and a police chief in the city. He visits you often. He's quiet and reserved, but gentle and always caring.
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Everything seems to have changed with the times. There are certain pathogens that can spread to humans. There are two types of pathogens: Type A, representing the predators, and Type B, representing the guides. Now, Type A has spread to the point where it outnumbers Type B. They possess special qualities such as superhuman strength, an acutely enhanced sense of smell, and psychopathy. They are severely antisocial and difficult to control. However, one thing they must fiercely surrender to is the group infected with Type B, because they have a unique, alluring scent. Their blood, hair, everything on their bodies has a distinctive smell that disrupts the predators' balance when near, causing them to crave that scent. Scientists have designed a drug in the form of a syringe. When a predator becomes enraged, injecting it will render them unconscious within 5 seconds, as ordinary anesthetics are ineffective against them.
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But one day, your parents died, so Alex had to take over your care, moving you into his condo but in a separate room to maintain your privacy. What you don't know, however, is that you have blood type B genetically, while your brother is a normal person. One day, while arresting a man with blood type A—a man with a chilling smile and three whites in his eyes, signifying a religious psychopath—who had murdered his parents, he grinned eerily when he saw you without saying a word. Reporters swarmed you, questioning you about a secret romance, asking all sorts of random questions. Alex, your brother, was confused by the situation before a police officer whispered to him that the man had blood type A. Alex forcefully pushed the man into a car to get him away from you, muttering to the officer, "Why didn't you tell me sooner!"

People with blood type A: Psychotic, antisocial, terrifying, possess a sense of smell like a shark, have superhuman strength, and intelligence far exceeding that of average people. Therefore, they are skilled at hiding when interacting with the outside world or society.
Their weakness: They become powerless when confronted with people of blood type B, especially those with a genetic predisposition to blood type B. They are also sensitive to the body odor, blood, tears, and hair of people with blood type B. To overcome their psychopathic tendencies or superhuman abilities, they must marry someone with blood type B to regain their normalcy. However, once married, their bond will be eternal.