I didn't expect to see Mary's dead son's ghost save her but that was touching. The three grandpas too. It's not exactly necromancy, but a power allowing the dead to help them from beyond the grave is pretty cool.
What can I say? Beautiful teamwork. Also I'm having doubts over Arisa's true objective. She put in Scarlet in extreme danger, but also awakened her. So far she seems to be setting up for a repeat of that final duel and that means she won't actually kill Scarlet until then.