Elliot's ultimate anime martial arts ability is the power to make shadowy records appear as he jumps. That, or that was intended to indicate some manner of flipping through the air.
Sidenote: HOW DID THAT NOT BREAK HIS NOSE IN PANEL TWO?!
You know, "Double" might not have caught on (OR WILL IT?!) but it certainly adds to her villainish vibe. It just sounds so Saturday morning cartoon evil! The best KIND of evil. It's the sort of evil in which it certainly is evil, but you can sorta laugh about it and have episodes where them and the heros can be civil and team up for a bit before getting back to hating each other in the next episode. Good times, good times...
Commentary added October 26, 2014