Although he’s been watching you and talking to you for a while now, it’s at this point that Colress realizes he never asked for your name, and then finds it out from you- and starts the battle, to see how good you are at bringing out the potential in your pokemon.  Colress packs a pair of tough steel/electric pokemon, so if you haven’t got good access to fire, ground, and/or fighting attacks you’re going to have a tough time ahead of you.  Grass types have a small advantage in their resistance to electric attacks, as do electric types like Mareep/Flaafy, but the resistance Colress’ pokemon hold towards those same types of attacks makes it mostly a moot point. 

Battle: PKMN Trainer Colress (2300 Poke)
Opponent: Magnemite Lv 21, Klink Lv 23
Opponent Item: Super Potion

On his defeat, Colress notes that in the same fashion as the major trainers- Gym Leaders, Elite Four, Champion- you bring out the power of your pokemon with kindness.  Thanking you for your help with his research, he gives you a Protein, and then laments that there is nobody around who can talk to pokemon so he can find out from the creatures themselves how their power would best be accessed.  Bidding you a ‘see you later’, he heads off to the North.

Continuing in that direction yourself, you soon come to some buildings you can enter.  The first building on the right, you can find a couple of ace trainers who are here not to battle, but to check your pokemon.  If any of them have a particularly worthy Speed or Attack stat, you can get a bonus item from one or the other (or both) of the aces here.

The next building to the north has a trainer in it who is looking for a Cottonee and willing to give a Petlil in exchange.  This isn’t a bad trade- Cottonee is an excellent pokemon for using status effects or such thanks to its abilities and speed, but Petlil is more useful in straight-up battling, having more significant Special Attack.  You can also pick up a Wide Lens by heading upstairs of that trainer, which can be useful if you have a pokemon with a lot of strong but slightly inaccurate attacks.

Keep heading North and you can enter a building on the West side of the road where a karateka will offer you some Sitrus berries, and apparently there’s a special event on Thursdays involving pokemon that use Fly.  If you can manage to get behind the house around then, you will find a Level 25 Mandibuzz- this wild pokemon can be caught and possesses Mandibuzz’s Dream World ability, Weak Armor.  Not the best ability, given Mandibuzz’s poor attack stats, but an interesting one nonetheless.