o ok well then u just have 2 wait and hope for luck. But here's a good way at getting a shiny kyogre, groudon, rayquaza, mewtwo, and the three legendary birds.
1. Save right before u battle the pokemon.
2. Battle the pokemon and turn off ur GBA if the pokemon isnt shiny.
3. Repeat step 2 until the pokemon is shiny.
Thats how i got my shiny kyogre, groudon, and rayquaza.
Only one image in here please