Through the RNG method you can get a shiny pokemon with great IV's as well as the nature and ability you want. Getting all of this together is very difficult because there's so many steps you have to do precisely for the IVs. Even with Smogon's guide and youtube videos I found myself getting frustrated trying to get all four.
I'd recommend to start with something easy such as getting a shiny poke, and work yourself up to getting those IV's :)
I'd recommend to start with something easy such as getting a shiny poke, and work yourself up to getting those IV's :)