Q: How does Mix It All Up work if my Keepers are “invisible” due to the Invisibility Spell or Magic Ring?

A: If you are Invisible when the Keepers are Mixed Up, then it works the same way it would your Keepers didn’t exist (since that’s what it looks like to the other players). Thus, all other players’ Keepers and Creepers (plus your Creepers, since Invisibility only affects Keepers) would be shuffled and re-dealt, with the Keepers you then received instantly turning Invisible.