Nana

ナナ

Also known as Number 7, she is a young Silpelit girl who appears to be 12-14 years old physically (though, because Silpelits age rapidly, she is actually only about 6 years old). Her name, 'Nana', is Japanese for the number seven, the identifier used for her at the research facility ("Nana" is also a fairly common female name in Japan). Most diclonius babies are euthanized at birth during sweeps of hospital maternity wards, but Nana was one of a handful kept alive to serve as test subjects; consequently, she has spent her entire life in the diclonius research facility. Kurama views her as his daughter and cares deeply for her. In an attempt to recapture Lucy, Kurama sent Nana out to locate her (diclonii can telepathically sense one another), intending for her to retreat until Kurama could arrive with soldiers, but Nana wanted to impress Kurama, so she tried to capture Lucy herself. Lucy and Nana engaged in a brutal telekinetic battle that ended with Lucy tearing all of Nana's limbs off. Kurama personally intervened to stop Lucy and save Nana, then also disregarded Director General Kakuzawa's order to kill her by providing her with new prosthetic limbs and setting her free with a large sum of money. Unlike many other Diclonius, because Kurama treated her with kindness, she is not homicidal or sadistic. She possesses the ability to temporarily disable other Diclonius' vectors by passing her own vectors through their pineal gland. Although her vector power is slightly superior to Lucy's in terms of range (3 meters compared to Lucy's 2) and certain abilities, she lacks Lucy's sheer strength (Lucy can lift and throw many more heavy objects than Nana can) and violent nature: Nana's empathy for others prevents her from fighting as vigorously, and she loses her arms and legs when she is viciously dismembered by Lucy. With her vector arms, she is later able to manipulate prosthetic appendages and even throw them like a rocket punch.
Nana can be seen as the exact opposite of Lucy. While Lucy's default personality is serious and cold, Nana's is friendly and kind; Lucy's split personality "Nyu" is similar to Nana's default state, while Nana sometimes goes into trances and acts cold like Lucy's default personality. Nana sits in the middle of the spectrum of Lucy's split personalities: she is not as mature as Lucy, but more mature than Nyu.