Powers: It can become an exact mirror image of anything
Captured in: Episode25: Two Sakuras
How it was captured: Mirror had made itself Sakura's twin. Sakura used the Clow Cards to receive a premonition that Mirror's target was Toya! After Mirror had caused Toya to fall off a cliff, Sakura confronted it. She had to say its name in order to turn it back into its main form(she didn't know it was the Mirror card yet.) The premonition that the cards gave her said that this card had something to do with Watery, Shadow, and Illusion. Sakura put the pieces together: water reflects images, shadow is like a body's twin, though not real but an illusion...the card was Mirror! After saying its name, Mirror returned to its main form, apologized to Toya for hurting him, and allowed Sakura to seal it away.