Eiro took a deep breath as he placed one of the books that he was reading on the table in front of him. None of them were really making sense in the way that Eiro figured he was supposed to learn to use Arcana. Of course, none of them were written speaking about Arcana in particular, but were simply theories about how non-elemental magic could potentially be used.
The Demon crossed his arms as he started thinking intensely. Maybe he could make some sense of these theories or figure out if there was some common denominator in them. Of course, that didn't mean that these books weren't useful to Eiro at all. It was just that they didn't mention anything about the Ancient Language, so it was clear that their theoretical methods for using non-elemental magic were simply false, at least to some extent.