Animation : Series Pilot Paradigm by Devon McBride-Wilson

I've written a pilot for an animated series that would have a lot of characters - and I mean a lot. A small rotating cast in every episode, but over ten total for the good side alone. But I've been mulling over how to properly introduce them and the world of the series - it has sci-fi and magical elements. Now, I've got a 'The Office'/'Spongebob Squarepants' type episode where a new person temporarily joins the evil side, and is shown around, and introduced to the bad guys, while a class of kids tours the good guy HQ. Though this takes up space, leaving the conflict lighter than in a usual episode. But many recent series with lots of characters or a large core cast use the model of a two-part opening episode to introduce everyone and everything - and set the story in motion. How would you handle writing a pilot for an animated series with lots of characters?