I'm sorry, but when did the main cast get involved in this act? Sure, I'd like to see it happen, but it's not at all going to imo.
I do believe that Meyer will make an appearance in this act, maybe aiding Sycamore/Platane in battle?
Hahaha lol. You are right off course, but i am talking about the possibility they are gonna meet in the main series. I like to see this. And yes, Meyer should appear in this act. Maybe he takes the Mega Stone from Alain back from Malva and returns it to him.