Steven seems to have already built up a reputation around the town, with Red looking up to Steven, and is currently in a relationship with Daisy Oak. Just like any ordinary Rival Battle, Miki and Mike's Squirtle fought, with Miki being the winner. Steven was once an ordinary trainer living in Pallet Town's outskirts with his starter Charmander named Miki, alongside his brother Mike. While the events are unclear if it succeeded in the first story, in Strangled and Door's open, you can see several distorted Charizards, presumably meaning Stevens plan worked. He does so, by murdering his brother in cold blood, believing that using his soul (via MissingNo.) he can bring her back. After a while of grieving, Steven eventually decides to try to bring Miki back.
While not much is known outside of the beginning of the story, Steven is portrayed as an obsessive, introverted man who loves his CHARIZARD (Miki) dearly, and was distraught over her death by his older brother (Mike).