Death looks so incredibly tired all the time, and a lot of it, he is too. Work is hard and there's always people who complain when it comes to the matter of dying. He is a pretty private person, so much so that most people don't know him on a first name basis.
Though Death is known for being a pushover a lot of the time, He can be stubborn and firm when it comes to his morals. However most of the time he doesn't quite care enough to get emotional about it. When heis mad though, people tend to leave him be and let him do as he so wishes. After all, he so rarely asks for anything firmly, when he does, people tend to be willing to compromise.