The chain might be for the weight on the other end.
Grapple, pull, sickle! Like Scorpion.
@N1ghtm4r3 I've tried to cut grass with a scythe (not sickle). Just from handling one you discover it's not great for combat at all. The ones who used them angled the blade in a way that made it into a spear or polearm.
Just like coke or pepsi. There's a reason some weapons are a lot more popular than others. Cool factor is a big reason. But the other big reason is that they are great for their task.
You might notice that exotic weapons are many times tied to a culture or area.
Like the dacian falx for example.