Oh, the Insanity!

We've talked about normal characters, and sad characters, and mellow characters; but what about the crazy characters? I have a talent of writing great insane characters (you would know if you read 'The Art of Death'). Being insane can come on many, many levels.
Level 1: Obsession with fire, blood, torture ect.
Level 2: Hearing voices/ seeing things.
Level 3: Burning things and/or harming people.
Level 4: Not being able to feel any emotional trauma after killing somebody.
Level 5: A emotionless serial killer that always escapes even with the highest amount of security guards there has ever been.
So, yes, many levels of insane characters. I like to play around with these in varying degrees of crazy with my characters. Remember something: Not a lot of people write books about bad guys who stay bad. Making a character go insane is a little tricky, but think about it this way. You are locked in a room that is very small and always quiet, what do you start to do? Talk to yourself and get so paranoid that you hear and see things.
Happy harming!