Yeah backtracking would be really boring without enemies. couldn't you make it so that enemies you have already killed won't yield any experience or gold? Maybe that wouldn't be as fun as that Symphony of the Night thing tho. Or why not make it so that you don't have to backtrack with the help of te...

I would want the enemies to get permanently killed just so that you can't farm. Farming isn't fun
Also if you are playing with perma death you are going to feel that you have to farm to make it through, which isn't fun at all in my opinion