To get Ho- Oh very quickly, start with or befriend a Squirtle in Waterfall Pond and raise it to level 50 and have it at Blastoise. Make it the leader and grab also a Charizard or a Venusaur, something at least Level 36, then take a Key to Mt. Faraway and go to 30F and use it on the locked room. There will be a Friend Bow. Equip it to Blastoise,who should be the leader, then go to 40F, disable every one your team member's moves, all 4 of them, and Ho- Oh will attack you. Then use some moves and knock out Ho- Oh and he might join you. If he doesn't, don't fret, he will stay till you get him.