A magic touch rewrite ideas.
Though the rewrite is going to be a while off I'm going to put forward the current ideas for it for you to have a look at.
Muse academy will become Slayer academy. Slayer academy will be still headed by the Muses but it will only train Slayers, it will also be placed in a pocket dimension where one hour in the real world equals one day in the pocket dimesion. There will also be changes to the Muse characters as well, they will no longer have dream-dust, they'll still be the legacies of Merlin but all it will grant them is more powerful magic and longer lives. Dora will be what, I am going to call, a reality bender, her magic allows her to bring any form of art to life, whether it be in the picture itself or out of it. Melody will be a sonic manipulator, her magic revolves around sound, which she can use as a weapon. Maria will remain a Shapeshifter but will no longer be restricted to just animals. Zoe will be able to remember everything she ever sees and hears to the exact details, in other words she's super smart. And Crysta will be able to mimic people and things around her, whether it be what they look or sound like.
Fae will no longer include species like Kitsunes, Angels, and Sirens, it seems too far of a stretch for them to be Fae. Imps, Fairies, Nymphs, etc. will still be Fae though.
Harry and Matilda find out about the Slayers later on. The idea is that the Saxton sisters are still Harry and Matilda's friends but they don't reveal that they are Slayer until they are around 13 or something, they will all go to Hogwarts together but the Saxton sisters will sneak off the Slayer academy during the night (which will be a week for them because of the time difference inside the pocket universe).
A new house is created when the Potters and Saxtons go to Hogwarts. I like Harry Potter stories where a new house is created by Harry so I think I'll add it, some of the other chracters (such as the Weasley twins) will also go into the new house.
When Sirius will still be a Slayer and was on his own Slayer team along with the Saxton sisters' mother, but before the first war ended something tragic happened that caused the team to break up and Sirius and the mother to turn their backs on Slaying. Also Sirius won't break out of prison until the third year like in the cannon.
When the Potters and Saxtons go to Hogwarts they find the hidden lair of the Vagabonds, a pranking group like the Marauders that existed three-hundred years previously, they then decided to become the new Vagabonds after getting encouraged by the portrait of the previous Vagabonds.
The Night market where the Potters and Saxtons get their wands will be more or less the same, only it will be named the Midnight festival and instead of those who are Fae leading the way it is those who know how to find it.
If I have any more ideas I'll add them.