To get Ho-oh in SoulSilver, You need to talk to a man in Pewter City (accesible after the Pokemon league) he is standing on a raised bit of land east of the Poke-mart. He will give you the Rainbow Feather, now go to Ecruteak city and go to the bell tower gate (in the Northeast of the city) and go through there until you get to the bell tower, the guy should now let you Upstairs, when you get to the top, you will encounter Ho-oh at Lv. 70 so make sure you have lots of ultra balls. It knows Punishment, Ancientpower, Sacred flame and safeguard so try to Paralyze it, freeze it or make it fall asleep before it uses safeguard.
