Oct 15, 2015, 05:29 PM
You need the item destiny knot. When two pokemon are in the daycare and can breed, having one of them hold the destiny knot will ensure that 5 random iv's will be passed from the parents to the eggs. So then whenever you get a new pokemon that outclasses one of the parents, you just replace that parent with the new pokemon and keep going til you get eggs that hatch with the iv's you want. Depending on what iv's the parents start with this can be easy or hard. Also the iv's passed down are random, so it can be time consuming. There are threads on this site that give away 5 or 6 iv dittos so I recommend getting on those threads so you have a universal parent that can pass down iv's.
