Evil Krillin was created by Tree Of Might.. He became evil because the Red Ribbon Army put some kind of chip in him making him evil. Goku and Evil Krillin had a long fight but, Evil Krillin was victorious.When everything seemed hopeless unexpected help came, it was.... ANDROID 19!? He betrayed Evil Krillin and took the "Chip" out of him.(Because he didn't think he was a good "Addition" to the Red Ribbon Army.) That was the end of Evil Krillin!
The difference between Evil Krillin and normal Krillin.