Since it's going to be a thing going forward, let's go over Revised Grimoires!
An Altered Grimoire is, as the title says, an alternate take on a story that can result in a stable, functional Magical Girl. Exceptions notwithstanding. Looks at Bell and her tentacle fetish. A Revised Grimoire can be either a standard or an Alter, but it's conclusion has been written over or added upon. The entire meaning of a story and its themes can be changed with just a brief line made from the essence of Pageless merged with the Grimoire, turning a story of accepting the inevitable into one of ceaseless struggle and opposition. The changes are not inherently evil but they are action orientated.
It does produce a change in the temper and behavior of the Magical Girl, pulling them into line with their Revision. They also have a connection with the Pageless that must be developed based on their interactions with Pageless. Further Revisions can made if they develop a strong grasp over the Pageless, allowing edits to be made to the Grimoire consiously at the expense of further impulsiveness and heightened emotions.
Beastial changes may occur with their Magical State, altering their form more animalistic charactertics or militant features.