When I say "major characters," I'm talking about trainers such as Cynthia, Cheren, Bianca, N, your rival, etc.
This does not include trainers in PWT.
Floccesy Town - Alder Undella Town - Cynthia Striaton City - Cilan, Chili &Cress Black City/White Forest - Benga Plasma Frigate - Colress Nuvema Town - Bianca Route 5 - Cheren Castelia City - GameFreak N's Castle - N (This varies in the season) (Long after this, after visiting him at the Ferris Wheel in Nimbasa on Fridays, you will be able to rechallenge N as he wonders about the previous game's Trainer and if he achieved his dream).
Source - Serebii Source 2 - N Hope this helps and what you looking for!
