Murderer (2006)

Set in a dark prison cell on death row, a serial killer ponders the meaning of his life, and decides to kill himself just to experience the rush of dying. He notices that every time he tries to kill himself, some other 'bad' person dies instead. He assumes he is dreaming, as he is also haunted by a strange creature like prison guard who appears every time he attempts suicide. The murderer tries to come up with bizarre ways to finally kill himself once and for all. Ultimately, there is a chilling confrontation between the murderer and the creature haunting him.