...and not Slipknot. My assumptions are that since he was on Arrow for two seasons including an origin story, they felt they couldn't use the character so soon. inversely, that's probably why we haven't seen captain boomerang on Arrow since his debut. But as for the jump rope/electro shock discussion, I honestly can't give you a "how" it's going be used, just that it seems to be symbolic of Harley Quinn's transition from Doctor to deranged. And like you said, the Joker is odd, I can't put anything past him. Any speculation on the goat? It's been really bugging me.