Lucy, whose real name is Kaede, is the central character of Elfen Lied and a member of the Diclonius species, a mutant subspecies of humans distinguished by two horn-like protrusions on their heads and the possession of invisible telekinetic arms known as vectors. Her backstory is defined by profound trauma and rejection. As a child, she was ostracized and abused by human peers who mocked her horns, an experience that culminated in a group of classmates killing a puppy she had befriended. This event triggered her first violent outburst, and she killed the children in revenge. This act marked the beginning of her deep-seated hatred for humanity, a sentiment that drives much of her early behavior. After being captured and held in a research facility for experimentation, she escaped, but a gunshot wound to the head caused her to develop a secondary, childlike alter ego called Nyu. Nyu is innocent, infantile in knowledge and speech, initially able to say only Nyu and later Kouta, and is incapable of violence. The presence of Nyu is partly a psychological defense mechanism, but also a manifestation of Lucy's own guilt and desire to hide her violent nature from Kouta, the only person she has ever loved. The two personalities switch under specific triggers: Nyu reverts to Lucy when attacked or struck on the head, while Lucy may consciously or subconsciously revert to Nyu when treated with kindness or when she wishes to conceal herself from Kouta. Lucy's motivations are complex and shift throughout the story. Initially driven by a cold and sadistic desire for revenge against humanity, she kills without empathy, often torturing her victims and dismissing humans as not real people. However, her feelings for Kouta are a constant source of internal conflict. She deeply loves him and feels immense remorse for having killed his father and younger sister eight years earlier in a fit of jealousy. This guilt motivates her to suppress her violent impulses in his presence and to seek his forgiveness, even as she continues to kill others. Her role in the story is that of a tragic antiheroine, a being created and shaped by cruelty who struggles between her destructive instincts and her longing for connection and redemption. Her key relationships are defined by this duality. With Kouta, she experiences her only genuine affection, but also bears the burden of irreparable harm. Her interactions with Yuka, Kouta's cousin, are marked by jealousy. With other Diclonius such as Nana, she shows a form of recognition but also a capacity for cruelty. Her development is a gradual journey from unthinking violence to a more conscious struggle with her nature. Nyu, over time, gains greater speech and awareness, while Lucy herself begins to show signs of remorse and even a willingness to sacrifice herself. In the finale, she promises Kouta to never kill again. Her notable abilities stem from her nature as the Queen Diclonius. She possesses vectors, invisible arms that can manipulate, cut, and grasp objects, typically within a range of about two meters. She can also use nearby objects as high-velocity projectiles to attack at greater distances and can deflect or stop standard ammunition. As the Queen, she is unique in that her vectors can transmit a virus to human males, causing their offspring to be born as Diclonius, making her capable of reproducing the species.