Howdy yall, I have been doing some quick google searches on this but I cannot find anything on what happens to the duelist that killed another duelist. Is it manslaughter? What if both parties are aware of possible accidents and witnesses were present? I do not mean modern times fyi
Except in the rarest of circumstances, you would face none. In those rare circumstances, you would almost always face a slap on the wrist. In the span of dueling history, the number of duelists who were convicted of murder and executed for it is basically countable on your fingers. I have several older answers which expand on this, including this one in particular.