That sounds like the Z Burst Dash Attack, "way above you" would be the Lightning Attack. But vanishing & reappearing way above... Aside from those 2, I have no other ideas. The only other idea I have is the Blaster Wave Combo, but that's only a small similarity.
Oh, I know what you mean now. Since you use the Gamecube Controller as well, I'll just tell you the button commands.
Smash them away (Hold A), and then use the Z-Burst Dash (Z + B while pursuing them). Once you reach behind them, press "Y > Y > A" and you'll do the follow up that the A.I are using on you. --- "Too bad he isn't me, who never loses and never almost loses." - xLashx http://www.youtube.com/user/snapaholic1