Suggested by Anonymous It’s time for a battle of heavyweights. Sigma is incredibly strong in the X series and has obtained countless power ups. In a straight up battle he would destroy Giovanni in seconds. What will ultimately hold him back here is just the fact that Giovanni has so many Pokemon at his disposal. Sheer numbers can actually come in handy at times and this is one of those times. Sigma just isn’t ready to face Mewtwo, Nidoking, Moltres, Persian, and the many other Pokemon that Giovanni has. They will ultimately rip Sigma to pieces. Giovanni wins.
DReager1.com 
I’ll take the machine-man over the Pokémon-stealing mobster any day of the week. Height, Technology, and everything else.
It’s a tough one because it is hard to go against a Megaman foe in any context. It’s just tricky because Giovanni has so many Pokemon. It would be like a whole army gearing up!