The Magic Guardian

The Magic Guardian is...

Sakura's Magic Guardian, introduced in Epidode 1, tells Sakura that ae is the chosen one to kill Miku, Reappearing in the New Year Special to tell Sakura that it is finally time to fulfill aer destiny.

Biography
In the New Year special, They state that they originally were a normal cat, owned by the original owner of Sakura's Sword, Neko Nekine. the Neko Nekine was killed, and all the sue-ness went to Them.