Rika said:
Well, Pokemon only become "evil" because their trainers are essentially evil. As Ekans once said in the anime (The "Island of the Giant Pokemon" episode), "Pokemon do bad things because their masters are bad." So really, in my opinion, it is humans who are filled with malice and hate, and since Pokemon respond to their traner's feelings, they too will succumb to doing bad things.
~Kelsey
I agree with this. It's the humans that can be evil, and then the Pokemon can follow their lead. BUT, however, some Pokemon may appear to be evil, and go on a rampage and kill others (doesn't Gyarados do this?) but they're only following their instincts, like animals. (I wouldn't call a bear "evil" because it killed someone - it doesn't think of morals and stuff like that).
Of course, some Pokemon (like Mewtwo) are very smart and human-like, and one would think that it can take into account morals and the like. But now thinking more on it, I don't think a Pokemon can really understand morals much at all, unless they're very smart and their trainers explain it to them.
So in conclusion, in regards to the First Movie, I wouldn't call Mewtwo evil. Why? If you know the background of his birth, including Ai (Amber) and everything, you'll see how he was deeply hurt, and couldn't really think of doing anything any other way, than by getting rid of humans. But then, when Ash gave his life to stop the fighting, Mewtwo had a change of heart, and was able to understand that what he was doing was wrong.
Hmmm... sounds familiar, huh? *cough*Jesus*cough*
-Trainer Rachel