So it goes like this
>collect cells
>once you have 10 cells and at least 1 core you can form a Zydoge (whose ability can be changed between Aura Break or Power Construct, I think?)
>collect more cells and cores
>each core also gives access to one of its three signature moves, ES or DD
>once you have 50 cells you can get a 50% Zygarde (also with AB or PC?). It can become 10% whenever you want as well
>only a Power Construct Zygarde 10% or 50% can become Zygundam during battles
>collect more cells
>once you collect all cells and cores, you can permanently change Zygarde's ability into Power Construct
>if you also have XY's Aura Break Zygarde, you can make Zygundam permanent somehow
Please correct whatever I got wrong.
Zygarde's whole deal sounds like a clusterfuck.