@BT: You know, it's funny. In Diamond, I chucked two Quick Balls at Dialga, because I knew of its high catch rate, and on the second try, I caught it.

I've always told people to not use their Master Ball on Dialga or Palkia, but people tend to not listen to me. >__>
You really got it Bold? That's good.

That's the best Nature to get for a Milotic, at least competitively. Just work on what I mentioned, and you'll have a pro Milotic in no time.
What's more funny - I caught Dialga with a
Standard PokeBall. Of course, I weakened it first.