Canalave City, nearby mines...
After leaving the Hoenn League headquarters, Yu Hai arrived in Canalave City and discovered that Steven was not at the company. He had gone to the nearby mines to dig for stones.
Upon hearing the news, Yu Hai was stunned for quite a while. He had thought Steven had stepped down as Champion to return home and inherit the family business. Who would have expected him to go digging for rocks? Rich people really did have unusual hobbies!
After learning where Steven had gone, Yu Hai came to the mines to find him. Not knowing Steven's exact location, he could only release Slowking and Lucario, letting the two Pokémon try to sense whether they could detect Steven's presence.
"Slowking." Slowking withdrew its psychic senses and suddenly opened its eyes. It had sensed a powerful psychic fluctuation in the distance. That was probably the trainer Yu Hai was looking for.
"Lucario." Lucario sensed it as well and opened its eyes alongside Slowking. There was a powerful aura in the distance. Was this the strong trainer their trainer wanted to find? It wondered which Pokémon would be sent out this time.
Yu Hai recalled Lucario, then raised a hand and placed it on Slowking's shoulder. "Slowking, Teleport us over there..."
"Slowking." Slowking sensed that powerful psychic fluctuation again, then vanished in a flash as it Teleported toward it.
The moment Yu Hai and Slowking appeared, they saw Steven sitting on a boulder and drinking water. A pickaxe lay beside him, still stained with dirt. He had clearly just finished digging for stones. A Shiny Metagross stood nearby as well, evidently waiting for Yu Hai's arrival.
It seemed that Metagross had detected them long ago. Both were Champion-level Pokémon; Slowking could sense Metagross, and Metagross could sense them too.