She is shown to have a playful personality to some extent and apparently likes to dance. "So foolish" is her favourite phrase, and she also knows how to speak German, saying "Ja" and "Nein". She seems to hold some kind of rivalry with Dalian, and they fight with each other a lot. Rasiel and her Keykeeper seem to be the ones giving out Phantom Books to people across the country. She can be manipulitive, seeing that she saw Mabel's sadness and used it as a way to give her the Phantom Book. She also seems to have been part of some of the things that happened in Huey's past.
Rasiel is a short young girl with short dark green hair. She has an eyepatch over her left eye with a keyhole on it. She is seen wearing a red and light pink dress with long sleeves, and wears black boots with purple striped leggings.
She is seen briefly commenting on the human race, asking why humans waste their time on destroying and rebuilding. She then walks over to a crying Mabel handing her a Phantom Book, telling her it "was a book for her." Rasiel is seen again in a room in a mansion when Ilas asked who she was. She asks him if he remembers and he replies saying it was vague, asking her why she was here. She laughs at this saying "So foolish. So foolish" and twirls around, souring through the air and lands on a chair, saying it doesn't matter, stating that she was only interested in his poems. He asks what it had to do with her and she ignores his question asking him if he knew what Phantom Books were. He said that he'd heard of them, stating they were books that gave the owner magical powers. Rasiel sours closer to him, stating that with a book like that, he could've easily read minds and calls him "Mr. Faceless Phantom". However, Ilas claims to not remember ever holding a Phantom Book and she asks him if he knew how Phantom Books were born. Rasiel states that since they looked like books, someone must've wrote them and Ilas asks if his anthology was a Phantom Book. However, Rasiel says that wasn't the case since there had to be conditions in order for it to be born. She states that there must be emotions strong enough to burn, like madness or fear and adds that his anthology wasn't yet strong enough but it could be considered the 'egg' of a Phantom Book. She goes on saying that wars were wonderful because they were the very torrent of madness that were the eggs in creating a full-fledged Phantom Book. Ilas asks her if she made Phantom Books but Rasiel simply says: "I'm a library. the Library of the Archangel Rasiel." She says she "holds all the secrets of Heaven and Earth" and Ilas calls it "the supreme mystery that no human could approach". She tells him that she would like his anthology to be added to her library after he kisses her hand. After Ilas gets shot down by Huey, Rasiel and Professor are seen under a tree looking at the damage done. She looks up at Huey's airplane stating he was a good reader and Professor tells her he didn't know about someone else who could read an incomplete Phantom Book. She asks him if he thought the man was a Keykeeper of another library and Professor replies saying that that would be fascinating. Ilas is seen coming out of the destroyed airplane, saying he'll have to make other poems. However, Rasiel states that it was over, souring over to him and telling him he couldn't go beyond the barriers and uses one finger to send him crashing to the ground. She asks him if he was really the Faceless Phantom, saying she had better expectations for him and gets up, looking at Professor. Ilas asks what they were and Professor tells him he wasn't just a knowledgeable bartender, stating that he brought him back from the grave. Ilas then remembers that he was already dead and Professor does something with the Phantom Book he was using to cause Ilas to scream in pain. Professor asks for forgiveness, saying he didn't have a reason to keep him in the world any longer if he couldn't complete the Phantom Book for them. Ilas asks if they were magicians but Professor simply states that it is a century of science, although there were no differences between the two. Ilas says that he just wanted to fly and after he disappears, Professor says he could do so to his hearts content. Rasiel is seen again in total shock upon meeting Dalian again, saying she didn't know she was still alive, calling her a 'doll'. After this a fight ensues between the two and Professor asks if she was welcoming their bright new day with a face like that and rubs Rasiel's face (which she didn't seem to mind). After it is revealed that they were after London, Professor shoots Huey but Huey manages to escape along with Dalian and Rasiel asks what he was going to do. It is then that Professor sends the zombies after them saying he was just planning to let The Mystic Archives of Dantalian rot, but changed his mind. After Huey destroys all the zombies, Rasiel states that that 'kid' was back. Professor states that he was too late since they had enough copies, saying no one can stop the destruction that is about to come. However, it is at this moment that Hal appears with Flam, using his staff to burn all the copies as Rasiel and Professor look in shock and dismay. They recognize each other instantly and Professor says that burning precious Phantom Books like that were crude. Hal simply says that they don't belong in the world and Professor challenges him saying that those who burn the books will eventually burn people. However, Hal states to have already burned people, even those dear to him with his own hands. Professor and Rasiel then turn around saying they would meet again, disappearing through the fire. Rasiel is seen complaining about how she came to England for nothing, saying they couldn't even ruin the rebuilding conference. Professor says not to worry about it since hard work gives birth to unexpected retaliation. As they fly off into the distance, Professor refers to Huey, saying the new world was already there.