Phillip
"Whoa!" He was surprised when she managed to catch the ball from that side. Instantly, Leon went to retrieve it. "I'm learning as I'm playing. You're right about that, though. Right now we should be having-" And then he smacks the tennis ball back with a top spin. "-FUN!" With enough force, he shot it to the other side of the court, opposite where Rhea stood. "Whew! A Pokémon battle? You should've said that in the first place! How about after a couple points here, we have ourselves a real champion time?"

It was something about this island that Leon is able to battle anyone at anytime, without waiting for any tournament or league from stopping him. So of course he was excited. "As for the league card, it's an item known in Galar to show what kind of trainer you are. You get to pick a special number, how cool is that?" There he goes, loving Galar, and trying to promote it more. Even though this girl already went there before.
Walter
She gave a hesitant nod to Leon before he sent the ball flying, running and stumbling a bit before ultimately failing to get the ball. It hit the wall behind her and bounced over to her feet, so she picked it up and stared at it with a slight sense of shame.

While communicating with Musharna to relay back to Leon, she turned back around and thought about how exactly to serve the ball, remembering they either bounced it or tossed it. So, she bounced it off the ground and hit it to start another round.
Beth
'She likes the idea of the League card, though she's never seen one. It seems like a fun thing to have and share around. Galar was mostly where her device comes from.' The Pokémon telepathically explained with a happy expression off to the side.

'As for the battle, she's well known for unpredictability. But, she doesn't dynamax, as she's heard of it here. We live in the Kalos region.'