User blog comment:B214/Volume 23 discussion blog/@comment-201.215.165.7-20170614013238/@comment-29963364-20170614025326

Pretty sure it was during vol.10, when Team Gremory went to the stadium for their Rating Game with Team Sairaorg.

Issei ran into Hades on his way to the waiting room with his team. Azazel stepped in, and after Hades left, Azazel told Issei that "he (Hades) dislikes everybody not part of the Greek/Roman Mythology. He especially hates Devils & Fallen Angels."

Azazel was then dragged away by Zeus and Poseiden.