The ability has some MAJOR "Hey Nifty!" to it and I really like that aspect ... but the usability is off. It's really hard to control the 2nd hit. Right now I'm just using a bot and the practice tool and I usually find myself accidentally autoing the target of the Q canceling the rubber-band immediately. I can't imagine trying to make that work in a team-fight.
Was the idea of a double cast explored? I know you probably don't want people to have to land two skill shots to make the ability good, but could you set up a Skill Shot followed by a Targeted?
Right now that's how I'm trying to make it work by hitting the Skill shot - hitting S to make sure nothing else happens then using A to help target my auto.
It'd be nice if I could Q -> Skill-Shot -> Q -> Click Target -> Rubber Band!
Obviously there'd be a recast window like Rumble's E or other similar abilities.