After finding out about the cards, it became a lot easier to search for them. However, Linfel also noticed something during his research. The information regarding the cards seemed to be suppressed in the Ventis Network. Unless you were looking specifically for it, you probably wouldn't just bump into it there.
That was most likely, so the various maguses and familiars wouldn't lose sight of their objective. In Linfel's opinion, it made a lot of sense. Those who still haven't massed the Magic Control Test should be focused on it instead of looking for those cards. As for the ones who had already passed, it was the right logical step to try to acquire one of those armors.