Avatar the Last Airbender is anti-fascist and also a great show all around.
However, I nominate Samurai Jack for best politics. Jack unites exploited peoples across the realm and even leads violent slave rebellions.
Bonus terrible answer: Pokemon, which is a capitalist hellscape fixated on slave-animal bloodsports.
I watched it but at some point they went really into the philosophy and I couldn’t understand it with the subtitles (or cause Chinese is really different). And then I stopped watching it (that was after like 3 or 4 episodes)
I enjoyed how much they went into the philosophy. It’s supposed to be an educational show for middle and early high school students