shinies are tough to get since i've been to Mirage Island,got pokerus numerous times,still no shiny,i get a feeling when i find one i'll kill it.
if lookin for a shiny wild, just go around and never put repels on. try finishing your pokedex, your bound to find one eventually. or... maybe not
i have a pokerus on everyother pokemon, finshed my nat. dex, i've done everything there is to do in ruby. still only 1 shiny
my bro [poliwag] has started over each game multiple times, accomplished a very large amount of the game, and still no shiny