As the title suggests, what is the darkest piece of writing you've ever written? 

Can include death, betrayal, anger, psychological or emotional dilemma between one or more characters. Did brother turn against brother? Best friends who followed different paths though they began with a same goal. A character being emotionally tortured by their own thoughts on love, alliances or success. 

These are just my own examples I came up on the spot but you can dive deeper with your own writing. 

Your darkest piece of writing, whether it be due to the scene being told or the analogies being used.