~Up your butt!~
He does not appear anywhere else
u talk or find steven in saffron city and he will give u a starter Pokemon
You get Groudon in Pokemon Heart Gold by trading with somebody who's found Groudon in Soul Silver. You can't find Groudon in Heart Gold, you find Kyogre. Soul Silver players find Groudon.
If you want to find heart decoration online, then you should go to ebay.com, amazon.com, or buy.com. Party city, oriental trading, and Kmart all have websites that sell the decorations also.
You can't find Steven Stone in Diamond
There is no such thing named the Steven stone
You don't find Steven in Mount Silver. You find Steven in Silph Co. after beating Red. He will give you a Hoenn starter.
You find Champion Steven at Ruins of Alph.
Once you give the doll to the copycat girl.When you come out Steven will talk to you about Latias.Use your poke'gear to find her.She will be roaming Kanto.
You can find Steven near the gym is Sootoplis City. When you find him, he will take you to the cave of origin.
Steven goes to the Pewter museum of science
No. The only 2 regions you can go to in Heart Gold and Soul Silver are the Johto and Kanto regions. However, you do meet Steven twice and obtain a Hoenn starter Pokemon. Also, you can find Latios/Latias as roaming Pokemon after meeting Steven for the first time.(Soul Silver=Latios, Heart Gold=Latias.)