^ I think we should rethink this because they did say those are 2 different phenomenon, Yuuko's just happened to go through both at practically the same time.
I meant the Becoming Center Nova Phenomena & Disappearance Phenomena are two separate things with their own set of requirements. Don't quite remember the exact have to rewatch, unless someone else list it for us
AFAIR : becoming C-N = Concert Battle + Weather Disturbance + High Dualium levels
Disappearance = Akibastar? + concert battle
wahh i'm getting confused will rewatch