The Ammit Cryas, also known as the Truth Grimoire, is a Grimoire that reveals the truth of one's being when looked into, but it will absorb those who stare too deeply into it. It has the shape of a hand mirror.
Initially, the mirror was sealed in a hidden room in the 15th Hierarchical City of Torifune, but was discovered by Team Remix Heart. It nearly gave away Mai's secret as the heir to the Hazuki family and Kajun Faycott's secret as an undercover Sector Seven researcher. They gave it to Professor Estella McKenzie, who locked it under several Ars Magus restraints.  Noel Vermillion broke it out of its sealing restraints, using it to find several tasks related to finding the Aedsqui Grimoire.  Chachakaka later took the Grimoire and used it to reveal Mai's identity when she was forced into a coma by Cypher Albar. 
- BlazBlue: Remix Heart, Chapter 04
- BlazBlue: Remix Heart, Chapters 10 - 11
- BlazBlue: Remix Heart, Chapter 22