Cresselia:My Bronzong held Quick Claw and used Block when it went first. The only damaging attack I had on it was Future Sight, so I hypnotized it and switched in Sneasel. It ran. I caught up with it again, and used a few Future Sights to get it in the red, and threw Ultra Balls, Great Balls, and Poké Balls. It struggled and fainted. I reset my game, and went and bought Quick Balls and Timer Balls. Repeated the process, caught it in a Timer Ball.
Mesprit: Mostly the same as above, except I caught it in a Poké Ball because Ultra Balls never seem to work for me.