Black Cat
Blacky went beserk when she heard the Father Shiro died and kept telling the exorcists that they were all lying about his death though only Rin could understand her (He said it may because they are both demons). When Yukio was about to use the item that Father Shiro gave him before if ever this scenario happens, Rin told him to let him calm Blacky down. In the end, Blacky accepted the fact that Father Shiro died and Rin and Yukio found out that the item that Father Shiro gave Yukio was actually his catnip wine.
Aired 19/06/2011EP 10 - Black Cat

Blue Exorcist
This world consists of two dimensions joined as one, like a mirror. The first is the world in which the humans live, Assiah. The other is the world of demons, Gehenna. Ordinarily, travel between the two, and indeed any kind of contact between the two, is impossible. However the demons can pass over into this world by possessing anything that exist within it. Satan the god of demons, but there's one thing that he doesn't have, and that's a substance in the human world that is powerful enough to contain him!! For that purpose he created Rin, his son from a human woman, but will his son agree to his plans? Or will he become something else...? An exorcist?