Nov 25, 2017, 12:54 PM
I don't know the exact mechanics, but I think the deeper you go, the higher the shiny chance. It is possible to sr them because their shininess is determined when you enter the hole. It's not possible to SR for a shiny one, only legendaries, because of the reason before. I think each ride is different so I don't think SR'ing for the same pokemon doesn't work.