That isn't a proper scyth. You could make a argument of a hand scyth, but the handle is to small I think. That is more a sickle IMO.
This monster seems to only spawn when I had more than 15 insight. Below 15 insight it didn't spawn. Then again, it might be because I already killed the area's boss.
Using the L2 attack of the two handed axe staggers them they become easy to kill if you use it.
During the Witch boss battle, these enemies seems to be blind, and wander around aimlessly unless you produce sound (running or attacking etc.). However, this is not the case outside the boss battle.. Which is weird.
I thought them spawning all over the ***** place was cause by me failing to kill the witches on the first try.. And here I was thinking they were the real challenge of that bossfight.