I was 17 when I purposely beat a man to death and permanently crippled another
That's terrible. Why did you have do that?
I wanted to kill all bullies in the world
It's a noble goal to stop bullying. But using violence to do it is not a reasonable solution.
I still feel good about it. I did what I wanted to do.
But don't you realize that you ruined their lives, and their family's lives? How did you think they felt when their sons would never return? You could have just tried to talk some sense into them.