When you get to Olivine City for the first time you will see a cut-scene featuring Ho-oh and Shadow Lugia. Then after talking to the woman (In front of ho-oh) you will enter a battle deciding if you are really the chosen one.
This Gym battle is hard it has one Rare Candy to defend aginst two gym leaders Chuck and jasmine.In the hacked version you get three rare candy to defend . If you win, you'll get the TMs Iron Tail and Focus Punch. The badges you will get is the Mineral badge and the Storm badge.
You can see Ho-Oh at the entrance of Olivine city. If you talk to it it will show you the cut-scene that you see when you talk to it upon entering the city. This cutscene consists of Shadow Lugia battling with Ho-Oh however Ho-Oh had the loss.
Mantine Morning Day and Night
Cutscene of a battle between Ho-Oh and Shadow Lugia when you enter