Wasn't there a time when Syaoran sees his other half reaching out the mirror, trying to choke him?
Maybe that symbolizes the darker half invading his mind.
It doesn't make sense that Syaoran would turn to Kuro-chan and asks, "Who... are you?"
It reminds me of the time when Asura went on a murder spree and tells Ryu, "Unhand me! Naga-oh!"
It's expected that Mokona fails to create the magic circle. They are in a world where EVERYONE uses magic like Harry Potter or that creepy place with the teapots in Alice in the Wonderland. (I wanna go to a cafe where teapots and dishes fly around. That's fun!) <-But that's not the point. There must be layers after layers of barriers in the library to prevent intruders getting out by any mean possible, should the barriers fail to prevent the break-in in the first place.
