All books.
A delicate and splendid crystal silver lamp hangs under the glass skylight, with ink-colored characters rotating around it like a ring of stars. The light, soft as mercury, brushes over the densely packed bookshelves. This is the largest library Ash has ever seen, or rather a labyrinth of books. He sits in the courtyard on the lowest level, looking up at an estimated dozens of layers of the library, truly feeling his own insignificance in the face of knowledge.
The spines of books in different colors are like treasured swords; they may be hidden here, unknown for the sharpness they contain, but when they are drawn, the entire world must yield to their brilliance.
