User blog comment:B214/Question and Answers 3/@comment-25222726-20140612183756/@comment-73.178.133.185-20140618132532

Rias and Akeno alternated doing the "ritual" between them. No one else initially participated because Asia was still a new devil and Koneko still hadn't fallen for him. The rest of the girls had yet to be added to the group. Having more than one helping ensured that someone was available in an emergency, so to speak.

As for the Bandersnatch and Jabberwocky, they were under Shalba's control and thus were sent to attack the Devils' side. They might have attacked the Fallen Angels' side if their territory was within their path of destruction, or if they went on a rampage after finishing off the Devils, or if Shalba retained control and was able to continue to command them... but things never got that far.