In this work, the magecraft used by Orlocke Caesermund.
Its premise is the inherent Mystery in the process of a butterfly changing to an effectively entirely different mode of life between the larval, pupal, and mature stages of its development.
As Orlocke himself described it, it is “the manipulation of the gap between what is certain and what is uncertain,” interference in the act of transformation itself being the core of this strain of magecraft. That was why he was able to transplant his memory and personality into a homunculus made from his own blood and semen.
Having caught the eye of the master of the Castle of Separation Geryon Ashbourne, he enlisted Orlocke’s help, and was able to create a method for transplanting Magic Crests into others. …though as the story describes, it was far from complete, and came with heavy side effects (though those side effects were Geryon’s goal from the start).
- ^ Butterfly Magecraft