>>149924240
Simple: they are reflection of the protagonist not just in the suit but outside of it as well- take the fairly odd parents for example: a crazy teacher, a mean babysitter, a bully, a comic book villain, beauracratic pixies who hate fun, a rich kid, a dentist, a sleazy genie- these are not only great oppositions to Timmy who is a naive ten year old kid but to his fairies as well, what makes them both threatening and compelling is that they aren’t only able to defeat Timmy but Cosmo and Wanda as proxies as well due to the inherent set up of the universe (Cosmo and Wanda cannot be discovered or else they’re sent back to Fairy World, Cosmo and Wanda can grant any of Timmy’s wishes as long as they are within the rules, and this world has magical beings living inside of it)

The writers use all of this to its maximum capacity and come up with fun reoccurring antagonists, and this isn’t even mentioning the villains who can also be allies such as Jorgen, Catman, Mark Chang, Tootie, etc all great foils and juxtaposition to the three protagonists and their personalities.