CH 5/2C causes that effect. As a follow-up, you can do: Dash 5AA, 2A+B, Killrush A, Corkscrew B. I'm not sure about CH j.C... I haven't really experimented with comboing off of it. Can't think of a way off of the top of my head either.
C is dash-cancellable so, you can use it for baiting(back dash) or pressure(forward dash). Sets up oki on normal hit since it knocks down.