>>470776881. Classes now exist for ALL Pokemon trainers and not just NPCs. For gameplay, this would result in small buffs to your Pokemon. Examples:
Bug Catcher: 10% buff to all of your Bug mon stats
Hex Maniac: 10% buff to all of your Ghost mon stats
Gambler: -5% to all of your moves accuracy, but all of your mons get a +1 stage of crit chance.
Ace Trainer: 5% buff to all of your mons stats.
Swimmer: 10% buff to all of your Water mon stats
Artist: +10% chance to all of your secondary effects from occurring (works separately from Serene Grace)
Harlequin: Forces your opponent to switch out every time it KOs one of your mons.
Kimono Girl: Eevee Pokemon get a plus 10% buff to all stats.
Janitor: 5% chance to clear out any field effects (Stealth Rock, Spikes, Rain, Sun, Screens) from both sides every turn.
Cook: Non-active Pokemon heal 1/16 of their HP every turn.
Doctor: 5% chance to fully heal all active Pokemon (including opponents). Does not include status.
Picknicker: Your pokemon that switch out get their items back if they are holding no item (if Pokemon had not item when switching out, then it does not get an item).
2. Instead of gym badges allowing higher leveled Pokemon to obey you, they now allow you to train Pokemon beyond certain levels and can be turned on/off. So for example, in Kanto the Cascade Badge allowed pokemon up to Level 30 to obey you. Now it would be changed so that if you did not have the next level badge (Rainbow), then your Pokemon would be stuck at a level 30 cap and could not level up any further.
