This is really the mentality many fantasy writers grasp during the process of telling their story, right? The decisions that the characters make in the course of their fictional lives defines them and their legacy, whether you actually kill the character in the book or not. BUT, when you do choose to kill any character (from the significant to the mundane), is it done to highlight the character and choices they made?
See, I get frustrated when fantasy stories include easy rescues for the heroes in order to keep the plot moving forward. This is one of the reasons I like Martin's Game of Thrones; he simply isn't afraid to eliminate a character, and he will always find a way to carry on with life (aka, the story). The threat of death is real in his stories, and even heroes can die. This realism makes readers think about issues like death and about how unpredictable life can be. This is a central theme that resonates with me. What themes will resonate with your readers?
As writers, we must understand death is a subject that makes people uncomfortable, and although our stories will tell of death, it should be done with purpose. People have emotional reactions to fictional character deaths. Some come to fiction to escape the concerns of their everyday life, but this is a certain avenue--especially in fantasy--that can rarely be escaped. And, when confronted with the sudden death of a beloved character, viewers and readers are jarred into dealing with the uncertainty of their own life.
How will you approach this topic, and what message will you tell?