Fisher guessed that the Creation Association must forbid its members from sharing the knowledge in their manuals with each other, as just possessing one was already enough to bewitch a person beyond recognition. Who knew what they'd turn into if they had more than one.
The problem was that if Fisher wanted to confront Erwin and ultimately kill him, relying solely on Elliog's "Death Rune" was not enough. Erwin's abilities were very peculiar, and conventional methods were hard to counter them with. Charging in rashly might likely result in a passive situation like back in Saint Nali, even if there couldn't possibly be another Elizabeth to devise a plan...
Could it be that he too must rely on studying the knowledge in the Soul Completion Manual to increase his power, to fight madness with madness?
Fisher pondered this but slowly shifted his gaze to the Demi-human Girls Completion Manual next to him.