>>25283393>>25283397>>25284081With all this talk about rainbow coloring, usage of the word niji having multiple meanings, and mega evolution symbol being similar in color. It hit me.
Mega X & Mega Y
pulled this out my ass and just a wild guess like everybody elses, but hell it would be unexpected yet follow GF logic even if it made 'Z' red herring unless they made it similar to the delta episode[/spoiler:lit] 