That's what I'm thinking. It doesn't necesarilly have to be one of the main cities we've seen up to now, like Demacia or Noxus but maybe one of the lands that hasn't been touched so much yet, such as the Shadow Isles.
The Shadow Isles seem to be a pretty miserably cursed land. I could imagine a pocket of resistance that's stringent on purging all the corruption that's present there, an oppressed cult when the balance of power shifted to the darker side of things (Mordekaiser and Eve are from the Shadow Isles if I recall correctly)
It could be in Urtistan, just on the other side of the great barrier, some type of hermit or monk that dwells there.