Lore Team: How do ensure characters don't feel too one dimensional or bland?

I think the new direction for the game's lore is fantastic! I'm really curious, though, how you guys avoid making characters too one dimensional or stereotypical? For example, many champions that come from Noxus are "villains." They have a dark or mysterious persona, often portrayed as a sinister figure of some sort.

That being said, how do you create a champion that's a true Noxian hero without being a one dimensional warmonger/dark figure/villain? Surely there's good and bad people on both sides of the lore per area. Jinx, for example, is a great example of a "villain" (more "criminal than good" or lawful) from Piltover in contrast to, say, Caitlyn or Vi. Is there a Noxian counterpart? Bandle City one? Dare I say Bilgewater or Shadow Isles?

I realize their home regions will reflect the richness of the history of the individual champions, but how do you stop from falling into the "all villains come from Noxus" pitfall?