A while back I read this series about an NKVD agent and a witch in WW2 going on adventures and stuff. The subject matter is grim but it is presented in a mostly light way. As in there are jokes, there's magic, and the characters are drawn in a cutesy manner.
In the final chapter, it's near the end of the war (Battle of Berlin) and the witch dies suddenly in a brutal fashion. A tank shell obliterates her entire upper body. Everything above the waist is just gone.
It has a happy ending1, but the first time I was reading this series that really blindsided me. The series does depict some rather grim stuff -- lots of death, atrocities -- but that last chapter death had an impact on me.
1: The agent wins a game against Death and makes her way to the underworld, where she drags the witch back to the realm of the living (and kisses her).