Nill is one of the only Darklight characters featured in The Legend of Zelda: The Twin Blades. She is very similar to Link in most respects, and in one possible ending for the game, Nill falls in love with Link.
Nill is a determined person, unwavering in her belief of the Hylian people, and that the world would never betray her. She is also naive for this same belief. However, she refuses to accept any sort of defeat, often charging in against insurmountable odds simply because someone told her not to.
The Legend of Zelda: The Twin Blades
Nill is hunting for Link, whom she believes to be Zelda's would-be assassin. She finds the Phantom Sword along the way. Ultimately, She fights with the real assassin, defeating him. She then enters Ganandorf's lair, only to be defeated and her sword broken.