"Although this thing can indeed store Black Magic Power, its magic power capacity is much less than that of a real Secret Art Crystal. Depending on the quality of the raw materials, it's roughly only one-tenth to one-third of ours, and each Crystal has only one surface that can store a magic circuit."
"At the same time, because the properties of the Magic Power cannot be repeated, in theory, each person can have a maximum of twelve of these Crystals in their brain, which means each person can have at most twelve fixed secret techniques."
"Moreover, since these are disposable, they have a fatal flaw compared to Secret Art Crystals: they can't actively produce Magic Cards, nor can they actively convert ordinary magic into Black Magic. Also, precisely because there are no Magic Cards, the Black Magic on these Crystals is basically fixed; once inscribed, it's very difficult to replace."
"That's still not bad," said Mu You.
