No one actually knows Izzy's origins or what she is. The most they know about her is that she is Nicks cousin and has known Ashes longer and more than anyone, not even her ex, who has known her since they were kids. Izzy tends to keep many secrets from people, not because she doesn't trust people, it's because she wants to protect people. The scribbles that are around her face most of the time is supposed to help her hide the truth from people. People can see many things if you look her in the eye. Your past, your future, how you die, when you die, somethings that someone else could be hiding from you. she also know the exact way to kill guardians like Shino. It's another reason why she doesn't talk much or interact with people.

thank you

thx =)