that's simple:
I rng natures and shinyness of the pokemon, then I save in front of the daycare oldman and then i hatch the egg he gives me, to verify if it is with the requested things. if it is i soft reset, Then I IV abuse it :) And check its IVs from the egg with the IVs code. :)
And I will RNG 4 pokemon is that ok with you? I will look at your wants and let you know