* Event Distribution: Suicune was distributed through various events in the past. If you have a copy of the game with a Suicune from a past event, you can use it.
* Trading: If someone has a Suicune from an event or a different game, they can trade it to you.
* Cheating: Using cheats or exploits can allow you to get Suicune, but this is not recommended as it goes against the spirit of the game.
Important Note: The methods of obtaining Mythical Pokemon vary from game to game and are often limited by the game's release period and distribution methods. It's highly unlikely that you'll be able to get a Suicune through official means on a current copy of Pokemon SoulSilver.