第 8 集: Mephisto 以狗形度過一天，與 Rin、Yukio 互動後回到與 Amaimon 會面的地點。

8

This episode is about a day with Mephisto in his dog form. First he is shown ending a conversation with Igor Neuhaus saying "I understand. You can leave now" and when Neuhaus leaves he directly transforms to his dog form. Then, he picks up a shoe in his mouth from a locker and buries it in Shiemi's garden. Later, Rin is shown eating and behind him on the floor Mephisto in his dog form have his lunch. After lunch, he sleeps on his own statue and Yukio is shown looking at him and then leaving. In the end of the episode he went to the incomplete building on which he met Amaimon for the first time in episode 5 after he transformed back to his true form. (Source: Ao no Exorcist Wiki)