I have an old scythe that was passed down to me by a friend's father-in-law before he died around 20 years ago. I would not want to ever get in the way of that thing if it was swung with malicious intent. It is very much a "fuck everything in this particular direction" type of weapon.
Now I'm starting to wonder if maybe that's where he got it from... It's very old. Maybe the reaper came and he managed to swipe it and gave it to me before the reaper had a chance to come back for him with a newer one.
Yup, they are very effective. Mine is a large two handed one with a curved handle (aprox 5 feet) and blade about 3 feet long, for taking down crops. Even slightly dull not many things put up much a fight with that blade and a good swing.