If he makes any aggressive move toward a person, better to get rid of him. I have never had success reforming a bad roo, but I have so many nice ones, it doesn't matter for me. I used to think there was some genetic basis, and there could be, but I just killed a really mean roo last weekend and his sons are wonderful, to the very last one. He just got too "uppity" and could not be changed. He attacked one time too many and now he is an "ex-rooster". I don't feel the least bit bad about killing him, it was inevitable.