Mega Man 2: The Power Fighters

I was looking at a sprite sheet for this game, and I noticed Mega Man, Proto Man and Bass have a fourth level of charge shot. This might be for Power Battle too, but I only saw it on the PF sheet. Anyway, how are you supposed to use it? Is there a pick-up, is it one of the "power parts" you get from Roll? I got all three of them, and there's just the one with the super jump that does anything.

Additional details - 4/29 10:33PM

Also, I saw something that looks like Mega Man has another special attack (the one you execute by holding up and releasing a full charge) other than his shoryuken, it looks like a one-two punch he does in mid-air. Has the same yellow energy around his hands like the shoryuken, so anyone know about that either?