As for Steven, Roman, and Adrian, with their talents, and their flames, they could participate.
Oliver, Calvin, Ryan, and Ethan still hadn't been given the green light to join this kind of battle and so they would stay with Cassy in the Divine Space to be able to keep up with the situation.
Mason would have liked to participate in this battle and have the strongest Warriors from each academy participate, but since they still didn't know where or whom these other superior Demons were, again they didn't have choice but to stay caution, and that's why they had brought elite troops directly from Spartia, so that no one else would know about their plan.
Mia had requisitioned Angel for two days and Freya as agreed had first sent to Astoria the 8 Mages who would fight with them.
As their number was limited, Mia wanted to make sure that they had all the chances on their side and so with Angel's assistance they helped these Mages create a bond with their flames.