How do you migrate from heart- gold to ruby?
You can't migrate from HeartGold to Ruby. But it can be the opposite. Pokemon can be migrated from Pokemon Ruby to Pokemon HeartGold.
you can't get suicune in platinum unless you 1. go on wi-fi (you have to have seen it to ask for it on wi-fi) 2. trade with someone from soul silver heart gold 3. migrate it from silver and/or gold (you can't put gold and silver into a DS, so you might have to trade it to Sapphire, ruby, emerald, leaf green, or fire red and then migrate it.)