He doesn't know why he tells the girl, who can't be older than twelve, those words. He's no longer Champion, no longer obligated to encourage hundreds of young trainers to take the League Challenge while knowing most of them will fail, no longer obligated to bring smiles to those same trainers. Her eyes light up with determination, and he realizes it was worth it. He knows that at her age, those kinds of words can inspire. He has no way of knowing if she'll be like the hundreds of trainers who give up at the fourth gym or the dozens who make it to the Elite Four only to find their dreams crushed under the League's strength. He finds that he doesn't care-her expression is that of someone who had been starving for encouragement.
He leaves her a copy of Steel Wing for her efforts (she'd brought a letter from his father, after all), his PokéNav number, and those encouraging words.
"If you keep training, you could even become Champion of the Pokémon League one day. That's what I think."
Despite his initial misgivings, it is he who approaches her at their next meeting on Route 118. She is soaked as she returns her Gyarados to a poké ball, murmuring what is likely praise for its hard work. He knows that she must have beaten Norman, the new Gym Leader in Petalburg. He does not know Norman well-one of his last acts as Champion was to instate the both Norman and Flannery as Gym Leaders-but he knows the man is strong.
He knows her mainly from scattered PokéNav calls at odd hours of the day, but he is fond of the girl. She always chatters about Pokémon she's seen and trainers she's met; she rarely talks about herself. He responds in kind, commenting on Pokémon and battle strategies and sometimes talking about the stones he's collected. He's come to seen her as a student of sorts, albeit one he has only met once.
Still, she looks happy to see him, as he calls out her name. Following precedent, he asks her about the Pokémon she's met so far. She only laughs, saying that since she had to backtrack to face the Petalburg Gym, she hasn't met many new ones. He chuckles in response, and for the first time he steers the conversation towards her.
He meets her again on a bridge in Route 120, where he is testing out one of his father's inventions. He has no interest in becoming part of Devon Corporation, but he has always tested out the devices his father sends. He offers her the device, asking if she's ready for battle. She is confused until the hidden Kecleon lashes out, causing her to stumble backward and nearly fall off the wooden bridge that really ought to have some sort of railing. He reaches out instinctively to prevent her from falling into the river below, though he cannot stop a laugh from escaping him. She glares at him as she releases her own Pokemon, a Shelgon, to face the Pokémon he knows she doesn't recognize.
It's the first time he's seen her battle, but it is obvious that she has grown from the first time he met her. He sees some of his own tips being put into action. It's flattering, to know that his opinions have shaped her battling style. He begins to feel like he really is her mentor. And yet, there are definitely strategies that he knows must come from elsewhere. He can't help but approve-she's obviously strong. That much is evident from the short battle, which ends with a Pokémon capture.
He no longer doubts his words from their first meeting. She probably could become the Champion.
He sees her next as she wanders into the Mossdeep Space Center. She is clearly here as a tourist, judging by the wonder in her expression as she wanders around. He waves her over and shows her the proclamation sent by Team Magma, knowing from phone calls that she's faced them before. He doesn't know why she started taking on the region's criminal organizations in her spare time, but he's grateful that she does. It has saved Wallace some work, in any case. He tells her to explore Mossdeep for a while, partly so that she can challenge the local gym, which he knows is her eventual target, and partly in the hopes that she does not have to fight Team Magma again. She is a strong trainer, but she is still a child. Thirteen, he recalls. She had mentioned it off-handedly during one conversation that it was her thirteenth birthday. Thirteen is no age to be performing the work of adults.
Team Magma attacks while she is away, and he is glad for that, even as they overwhelm a majority of the Space Center's employees. In the end, he is the only one left to challenge them, and he is outnumbered. Even with his strongest Pokémon at his disposal, there is risk. Risk that a stray attack would obliterate important equipment or support structures. Risk that he cannot afford to take, so he settles for a team he has had less time to train. His Pokémon are still strong, but he knows he is outnumbered.
He is simultaneously happy and horrified when she appears in the doorway, her Pokémon out at her side. He knows that she must have left a trail of defeated grunts in her wake. He hates that she has been dragged into these affairs yet again, but he asks her to assist him with the last few members of Team Magma. His Pokémon are on their last wind of strength from all the previous battles, and he still does not want to bring out his strongest unless his hand is forced. She and her Pokémon don't need to be told twice.
They work well together, he discovers quickly. Their Pokémon move in sync, and they make quick work of the last members of Team Magma. As they wait for the police to arrive, he invites her to his home.
He has another gift for her, this time the TM containing Dive. She will need it to go to the last gym standing between her and the Elite Four, the one in Sootopolis. He does not have much else to offer-his home is sparse and everything is coated in a thin layer of dust. He does not spend much time at home, preferring the dark caves of the region for their mining opportunities. She wanders around, looking at his rock collection while she sips at her tea, the only food or drink he has to offer. When it is time for her to leave, he walks her to the shore. She hugs him tightly, and he is reminded, yet again, that she is a child. He wonders if she'll be all right as she hops onto her Gyarados' back. She is a child who has been forced to fight battles that should not have been hers. He can do nothing but try and make the rest of her journey smoother.
He finds her sitting in a shallow part of the ocean in the torrential downpour. Despite his Skarmory's protests, he urges his Pokemon to take him to her. As soon as he lands, she is clutching him, sobbing. Her tears are hot, a sharp contrast from the cold rain around them. He holds her long enough for her to explain what happened with Team Aqua and for him to make an attempt at comforting her, but emotions have never been his forte. He eventually leaves her, knowing that he has to meet Wallace in Sootopolis, with instructions to stay safe and knowledge of his intended destination.
Thus, he figures he shouldn't be surprised when she surfaces in Sootopolis Lake, practically in between the two warring legendaries. Despite the storm, he can hear her yelp in surprise as she urges her Gyarados to shore, where he and Wallace are. He almost wants to yell at her for following him, but he recognizes the determined look in her eyes. She will get involved with or without his approval. In the end, he introduces her to Wallace, who leads her into the Cave of Origin.
She returns from the cave with purposeful strides, and he knows she's going to try and fix things. He is worried, but he decides to place his trust in her. She has proven herself capable, as much as he hates to admit it.
Still, he sweeps her into a tight hug once the crisis is over, lecturing her for her recklessness while praising her for her bravery.
He feels bad leaving her with a rather impersonal note that she may never receive. Wallace informed him that she had indeed become Champion of the Pokémon League shortly before he left home. He imagines her bursting into his house in Mossdeep, the good news on the tip of her tongue, only to find dust, a hastily written note, and a poké ball containing a Beldum. But what he wrote on that letter wasn't a lie. He was soul-searching. He was lost, unsure of what he wanted to do next. He had once sworn off of competitive battling, but acting as a sort-of-mentor to her made him miss it. So he runs. His Pokémon are unsure of the move but ultimately supportive. They are confused by the daily training sessions coupled with days spent mining.
He travels, first within Hoenn, to visit with old colleagues. He learns, for the first time, that Norman is her father. He almost laughs at himself for not figuring it out-they have the same eyes. He then goes to Kanto, then Johto, and then Sinnoh. He spends most of his time dabbling in odd jobs or research or, in the case of Sinnoh, mining. But he still trains his Pokémon, and realizes that he cannot escape being a Pokémon Trainer. He begins to wonder why he tried.
She finally catches up to him, when he is visiting Meteor Falls out of nostalgia for the region of his birth. It has been years since they've seen each other. She is now an adult, if he's properly kept track, and they have not spoken since the incident in Sootopolis, save for his annual birthday message. She is shocked to see him, but also angry and elated. He can't help but wonder if she's searched for him in the past. He doesn't make excuses for himself as she lectures him for not keeping in touch. Instead, he challenges her to a battle. He is curious about how she has grown in the past five years. Newspapers tell him she is still Champion, but he wants to see her power for himself.
Their battle is as intense as he has imagined-it consumes his attention and reminds him why he loved competitive battling in the first place. She wins, in the end, but it doesn't feel like a loss. He smiles and tells her, similarly to their first meeting, that he has faith in her abilities. That he thinks she can go as far as she wants. She accepts his praise gracefully, but extracts a promise to keep in touch before they part ways at the nearest Pokémon Center. She returns to the League, looking like she doesn't want to go back, and he is left once again with more questions than answers.
He has no idea where he will go next, and he has a suspicion that she feels similarly. He wonders when the position of Champion will become too stifling for her. When she will decide to take off and visit other places, the way he did when he first stepped down.
He decides to become strong enough to become Champion once more, in anticipation of the day she too decides to become free. As the mentor who abandoned his protegee, it is the least he can do.
And he would be lying if he claimed to be entirely averse to the idea.