I support Magi and Fairy Tail for best full cast.
I support Fairy Tail because for a mainstream action manga, it's cast has more prominent female characters than other action manga I've read, and I think the author does a great job designing each one to be individual, along with their personalities and power capabilities. Minor characters get plenty of love and attention despite not doing much plot wise.
I support Magi because the character designs for each and every character is nothing short of awesome. Everyone looks different, has different power capabilities, and they carry themselves differently. I also think there's a good display of gray morality. Instead of people being "good" or "bad", people have loyalties to different countries, which can make them either good or bad considering on the political environment of the country.
Also, power can mean different things to different people. You have characters who identify as Fanalis--they are literally the strongest race on the planet. They can tear people apart with their bare hands. And yet, they can be matched (not outclassed, matched) by magicians, who solely rely on magical power. But not just any magician, trained and skilled magicians who have graduated from magic school. And then you have people who are djinn users, who are neither magicians nor rely on brute strength, but rely on djinns for extreme power in short bursts. There are few people who are masters of everything, but even then, they aren't untouchable. Magi has a good system of checks and balances in terms of power and ability.
