I cant find steven who is supposed to be in vermilion. Where is he? (Heartgold)
You need to collect the Copycat's Clefairy Doll.
>he player will first meet him after they have left the Pokémon Fan Club in Vermilion City after collecting the Copycat's Clefairy Doll, in which he will appear and inform the player that there's reports of either a LatiosSS or LatiasHG roaming Kanto. -Bulbapedia