How do you get Ho-oh in Pokemon firered without going to a special event k?

You can't catch Ho-oh unless you go to an event, however you can get one in Pokemon colosseum to do that train or trade Pokemon in colosseum and use your story mode party in mt battle vs 100 go through it without losing all your continues and you will get ho-oh. To do mt battle vs 100 on the main screen of colosseum choose colosseum battles on the right then pick mt battle vs 100.