"Things are very different in my home region. A lot of what I knew wasn't directly appreciable."

(Don't ask if he means "applicable." People don't like it when you correct them, even when they're wrong.)

"...Would you mind showing me?"

He grimaces. "I am ... a trainer ... myself, and I would be interested in seeing what is so different about your style."

"Of course. Amadelphous, let's show him what we've got!"

He doesn't give his Pokémon nicknames. They're temporary companions, equal partners, not pets.

He sends out a Blitzle. It was fortunate that the gym leaders decided to pair him up against Cress, when there are Blitzle so close to the city.

"Blitzle, use Shock Wave." 

The Blitzle sends a jolt of electricity towards Amadelphous. She chirps indignantly.

"Amadelphous, hit it!"

She runs towards the Blitzle, slapping it twice.

"I see. So this is what your Pokémon meant... Blitzle, use Shock Wave again."

The Blitzle releases another jolt of electricity.

"You're tougher than it is! Keep hitting it."

She lands three solid hits, this time.

(Don't look upset. Normal trainers don't get upset about things like this, and you need credibility.)

"Blitzle, try using Charge this time. Save up your power."

It's a gamble, either way is a gamble, but if the Blitzle can land a particularly strong hit next time, it could synergize with the charge.

(He's most likely going to lose the battle regardless, but that's besides the point. The point is what the Audino has to say.)

"Keep hitting it while it's distracted!"

Amadelphous launches herself towards the Blitzle, landing five hits this time. 

It's just enough to knock the Blitzle unconscious. Sometimes you gamble and lose.

Chirp chirp!

He counts out some money. The fact that people can earn money from battling isn't a worse wrong than the institution of battling is, but it still feels distasteful.

"Thank you, Sebastian. I ... didn't expect to hear such things from a captive Pokémon."

"...I didn't tell you my name."

"Your Pokémon seems to know it perfectly well."

"Is there anything else she wants to tell me?"

"She mentioned earlier that your battling style was quite unusual, and I see what she means. Would you like some advice?"

"I'd be honored to learn more about Unovan techniques." Maybe if he says it like that it'll sound like he's foreign, rather than just that he's incompetent.

...Hopefully it doesn't turn out that the secret to not mistreating your Pokémon is something unique to his region.

"Most Pokémon know a few especially potent techniques, which we generally call 'moves' for short. When you first met your Audino, she was confused about some of your instructions, though she's figured out by now that when you command her to hit things you're satisfied with what scientists generally call a 'double slap' technique. That's certainly fine for now, but as your journey continues, you'll likely want to make use of other techniques as well."

And probably you'll want to catch more than one Pokémon, but that clearly crosses the line into advice that's unethical to give, no matter how nice he might seem.

"How do I determine which techniques Amadelphous knows how to use?"

He cocks his head to the side for a moment. "Currently, she can repeatedly hit another Pokémon, as you've seen. She can also attack another Pokémon with her forelegs — we call that 'Pound' — intimidate an attacker — 'Growl' — or clear herself of ailments, though not well enough to restore her energy — 'Refresh.' Assuming her Pokéball is registered to you, you should be able to check up on that yourself, though that won't provide as much information on what she's good at."

He shows Sebastian how to do that, and while he's at it how to estimate how much energy his Pokémon has left.

"Thank you."

He glances at the Pokémon Center. "I should get ready for the night. Will you be staying here as well?"

Headshake. "I'm not done travelling for the day."

He waves goodbye. (He doesn't stop by the Pokémon Center to get his Blitzle healed.)

That doesn't register as unusual. It matches most of the trainers he's fought so far.