As far as I know, you can only use one power item at a time. You cannot pass down two IVs by using two power items.
Oh, I thought it was possible to do so. Now, breeding for a Munna just became easier, and harder. Harder in the sense of good IVs, but easier in the sense of natures, aloures come up so often that there HAS to be a good IV mixed.But anyways, thatnks for clearing that up for me.