Ethan lives on Mandarin Island South and runs a pretty clever operation: he keeps a bunch of Magnemite around to provide backup power to the local towns whenever the grid goes down. His Jolteon helps him wrangle them. Most of his Magnemite are totally devoted to him, but there's one he calls Number 6—his self-described "black sheep"—that's always been a bit of a problem child.
During a run-in with Team Rocket, Ethan and his Jolteon both took a beating. That same day, the local Pokémon Center lost power right when they needed it most to treat sick Pokémon, so Ash stepped up and offered to haul Ethan's Magnemite into town to get the electricity running again.
The trip didn't go smoothly. Team Rocket showed up again, this time covering themselves in static electricity to lure the Magnemite away. But seeing his friends in trouble snapped something in Number 6—the troublemaker actually came through, evolved into Magneton mid-rescue, and sent Team Rocket packing. With that crisis handled, Ash managed to get the Magnemite where they needed to go and restored power to the town.
Content compiled by AnimeList.moe from publicly available sources.