She is not Blind.

Nill enjoys listening to everyone talk.

Naoto's voice is soft and calm; she gazes at Nill like she was her sister and always talks to her about womanly things that she knew it would be nice to know. Sometimes her voice could become sad and Nill would go up to her and hold on to Naoto because she knows what it's like to be alone and without anyone to do this to her.

Bishop's voice is loud and obnoxious, though sometimes it could be quiet and serious. She enjoys listening to him with either tone he uses, especially while doting on her while trying to teach her how to read. Despite him being a perverted priest and her being his little Lolita-fantasy come true, she trusts him. Trusts him because she knows he's harmless.

Badou's voice is also loud, but not as obnoxious as Bishop's could be, but again, it holds another side to it, he can also sound remorseful about the past or doing something wrong. She hates seeing him like that and hugs him as many times possible, before she gives him an equally sad look, because she feels his pain and wants him to be happy.

Haine's voice is like a double sided blade, it could be soft and gentle towards her and his few friends and loud and taunting towards his foes, she doesn't like listening to him when he's using the latter-voice, it makes her feel insecure and sad, because she knows he's drowning in a pool of regret and sadness that no one could pull him out of. She tries, though, she tries doing things to make him happy.

Nill is not blind to the hurt everyone feels, in fact, she is adept at sensing it. If she could talk, she would look up at each one of them, give them her best smile and tell them that everything would be all right, no matter what.