Why create, when it will only be destroyed? Why cling to life, knowing that you have to die?
~ Kefka Palazzo
This is what happens when you dummies try to think! WE'RE ALL JUST TRASH WAITING TO BE THROWN AWAY! THAT'S ALL A TOY IS!
~ Lots-O' Huggin' Bear's nihilistic beliefs on toys
Let me tell you something about me. Life is the most valuable thing we have, right? When you take a life, that should mean something, right? When I killed my brother, I felt nothing. No guilt, no remorse -- nothing. And he was the one person in this world I ever gave two damns about. They lied to me -- about the importance of life. The only life anybody really cares about is their own and I don't even care about that. You understand? I'm just killing time, waiting to die.
~ Deadshot's beliefs regarding the importance of life
A Nihilist is someone who believes that life has no purpose, value or meaning, their own included. Nihilists do not believe in the existence of any objective morality, and any rules/code they follow, if any, are superficial or only due to practical reasons. They usually do not have any specific long–term goal or purpose, will sink to any level of depravity to further their arbitrary objectives, and are often sociopathic and/or suicidal.

Many Nihilists wish to destroy everything in existence, or at least whatever it is possible for them to destroy. What makes them dangerous and unpredictable is that they have nothing to lose, not even their lives.

Because of their view of life as meaningless, Nihilists can often surpass into suicidal. In some cases, they also qualify as Pure Evil, largely because they do not see any value in morality and go out of their way to prove morality and decency to be meaningless by doing extremely depraved actions.

Perfect example of Nihilists are Kefka Palazzo, Joker, and Melancholia St. Clair.