/vp/ I need help,

From what I understand, getting a regenerator Ho-oh, Multiscale Lugia, and other specific hidden abilities on legendaries, I have to grind dream radar until the end, and then use the respective cartridges to capture them, and finally transfer to BW BW2.

This is all fine, but how do I get the right natures that I want with each? Please help anon, Ubers looks fun