Haha!
I just got into the series and I enjoy it. That's a major shift in art style there, but I guess you wanted Mastermind to be more movable.
The animation is fantastic already, but maybe putting motion blur between symbol frame change or something will get rid of some of that blocky feel. Idk, I can't claim to be any smarter than a monkey about flash.
Butbut TLDR, that was fantastic. Keep doing what you're doing and upload #6!