|"Reach 100% good or evil, or see another Hero do so."
Fable 2 Achievement text.
Reaching 100% evil is far easier than reaching 100% good. All you need to do is simply go into any town and go on a big killing spree, killing all of the guards and innocent people that you encounter. When you reach 100% you can reset your Xbox without saving it if you don't want the consequences of being so evil!