Things You'll Need
Instructions
Go to Hearthome City, located between Routes 209 and 208. Enter the Contest Hall.
Insert a berry, such as a Ganlon, Wiki or Oran berry, into the Berry Blender machine. Press "A" when the rotating arrow points at the marker. You get an indigo or blue Pokeblock, depending on the type of berry used.
Open your backpack and select "Key Items." Select the Pokeblock Case. Select the Pokeblock that you just created and choose Feebas as the Pokemon you want to feed it to. When you do this, Feebas' beauty stat increases slightly.
Continue making indigo and blue Pokeblocks and feeding them to Feebas. To see Feebas' beauty stat, select the "Condition" option in the Pokemon Status menu. Feed Feebas more Pokeblocks until its beauty stat is full.
Battle with Feebas until it gains enough experience to level up, or just give it a Rare Candy to level it up immediately. When it levels up with maximum beauty, it evolves into Milotic.