How did the Cody infinite loop work?

When Cody uses his mass attack, does he attack with his basic? I guess that would do it. Echo would attack twice (once from the mass attack, once assisting Cody's basic). If all 50% went to Cody, and he can get 60% from his own attack.

I thought it would be something to do with CS1 getting 50% from attacking (calling echo), then 50% from the cody special, and somehow Cody gets enough that he and CS1 keep going back and forth. But it wasn't adding up.