Rust is a playable character after collecting all 25 effects, and then going into flow while in flow, thus examining you computer while in this state. Rust looks a lot like Sabitsuki, but with one difference, her hair and clothes are more detailed and her skin is more pale and her eyes are a very very very deep red instead of black. She can do many of the things Sabitsuki can, but cannot collect effects. However, Rust can access three areas where you were not allowed to enter. There are more red demons when you play as Rust in areas where Kaibutsu have previously been, or new areas.