A great book that not only expands on existing options to have practices influence game mechanics but also offers a more nuanced take on evil practices beyond 'Kill people for infernal investments.' I personally did not like how high power characters had to make a permanent choice between versatility or specialization but the idea is one I would love to include in my games after a bit of homebrewing to make it so that the choices merely cause an increase in experience cost rather than permanently banning sphere advancement.

This book allows Mages to wield the powers of their characters aesthetic without a large experience cost and debate on whether a certain sphere should be at two dots or three dots for a certain effect.

For example if you wanted a mage with prophet aesthetic you would need prime to alter your aura, mind to inspire people the same way divinity does, life to heal the sick and matter to create food. Glory minor sphere can do all of that but it is balanced by the fact that it can only do those things.

However in my opinion the real charm of this book comes from the fact that it gives a framework for individualizing a Mage since when players use these you no longer have situations where two Hermetics have the exact same powerset because they both have three dots in Forces. Instead one of them has three dots in air and water while the other has three dots in fire and earth resulting in them complementing each other rather than stepping on each others toes.

I highly recommend getting Prism Of Focus book alongside this one as that too offers a wide variety of customization options and by using them together as a Storyteller you are guaranteed to have unique NPC's for each situation and as a player you are guaranteed to be able to add such a nuance to each of your characters that you could do a similar character to your last character and have an unique character anyways.