For the Gordor battle, I used a Donphan on Raikou immediately after the lightning stopped, and he was an easy catch (I didn't take any damage). For Suicune, I used a Grovyle assist, which got rid of his clones (Again, no damage). Entei was the hard one. I suggest waiting for him to get into the middle of the screen with no flame geysers nearby, hitting him with a bubble from a water-type, and circling like mad. Power circling will help you against all three of them, just make sure you're accurate, otherwise you're going to be in a world of hurt (well, maybe not you, but your styler will).