It's really frustrating to kill pokemon you want to catch. I swear i had to reset the DS like 100 times so i could catch a Ho-oh
Atleast for legendary Pokemon you can save the game and basically guarantee yourself the pokemon. I had no warning for that damn Whismur. I agree, though, it is really annoying when the pokemon is so hard to catch that you have to reset heaps of times before you get it.
Mewtwo was such a badass. 
