I guess. But nothing says the Champion can't be Voodoo-esque, right? Not totally Voodoo, but definitely inspired by it.
For instance, what if you were to not make this Champion a shaman or witch doctor, but instead a "Voodoo" deity? As in something like this!
http://imgur.com/pi27oIf
Here's the story I'd have for this particular idea:
Long ago, in the Kumungu Jungle (where Nidalee and Zyra come from), there lived an ancient society that worshiped old gods that, today, is long-extinct. Centuries ago, these people were wiped out by an invading army, despite how fiercely they resisted, and despite the efforts of a powerful shaman who led them.
On the eve when they would become extinct, the shaman performed a ritual to a powerful, but evil god (whom I'll call Gobomba for this) to smite the invaders, knowing that invoking the dark god's wrath would certainly spell the end of their people. During the ritual, the shaman is killed, but this ends up stirring the evil god Gobomba, who unleashes a terrible curse upon the invaders, utterly annihilating them via a magical plague. This plague, however, also killed those who had summoned him, leaving no survivors.
Centuries later, an expedition into the Kumungu Jungle finds the dark god, Gobomba, now corporealized inside a large wooden idol. They disturb the dark god, angering him and bringing forth a terrible threat upon Valoran.
That's just a rough draft, but do you think it could work?
