Steven Stone, known as Daigo Tsuwabuki in the Japanese version of Pokémon, is the Elite Champion in Pokémon Ruby and Sapphire. In Emerald, he becomes a powerful wandering Trainer after passing his title to Wallace. A master of Steel-type Pokémon, Steven's team is anchored by his Metagross.
He is the son of the president of Devon Corporation, and both father and son share a passion for collecting rare stones. Steven resides on Mossdeep Island. After players defeat the Elite Four in Pokémon Ruby, Sapphire, and Emerald, they find that Steven has left them a Beldum and a note.
In the anime, Steven made a single appearance in the episode "A Hole Lotta Trouble." He assisted Ash, his friends, and Team Rocket in escaping an underground cavern. At the episode's conclusion, Ash pledged to train harder to one day be strong enough to challenge Steven.
In Pokémon Adventures, Steven encountered Ruby while exploring Granite Cave. During a battle with wild Mawile, Ruby’s Skitty inadvertently triggered the evolution of another Pokémon by bumping into one of Steven’s Moon Stones. Recognizing the threats posed by Team Magma and Team Aqua, Steven invited Ruby to join the fight against them, but Ruby declined due to his dislike of battling. The devices on Steven's arms are tools for chiseling away at rocks to retrieve those out of reach.
Later, it was revealed that Steven and his father knew about the schemes of Team Magma and Team Aqua for some time. Mr. Stone developed the Submarine Explorer 1 to seal the Seafloor Cavern, preventing anyone from awakening Kyogre and Groudon. If this plan failed, their backup was to unseal Regirock, Regice, and Registeel.
Steven then assembled the Hoenn Elite Four to combat Kyogre and Groudon. With help from Sapphire's Wailord and Relicanth, they managed to unseal the Regis. Steven took control of Registeel, assigning the other two to fellow Elite Four members. Knowing his fate in the upcoming battle, Steven stepped down as Champion, returning the title to Wallace. After Kyogre and Groudon returned to their domains, Steven seemingly died from controlling the Regis but was later revived under mysterious circumstances when Ruby released his Celebi.
Steven traveled to Sinnoh to collect rare stones found there, purchasing a villa which he later sold to Platinum before returning to Hoenn. Using his Metagross, Steven flies around Hoenn, floating atop it thanks to its magnetic abilities.
