Ken does a series of kicks that eventually form a tornado of sorts through the air, knocking the opponent diagonally through the blast zone.
Shippu Jinraikyaku first appeared in Street Fighter III: New Generation as one of Ken's selectable Super Arts, and also appeared as one of his many super moves in Street Fighter Alpha 3 and the Marvel vs. Capcom games. While it did not appear as a Super or Ultra in Street Fighter IV and its revisions, Ultra IV reintroduced it as the Omega-exclusive EX Special version of his kick specials.
A variation of the move called Kuzuryu Reppa (九頭龍裂破, Kuzuryū Reppa, "Nine-Headed Dragon Rending Blast") was introduced as one of Ken's Meteor Combos in Street Fighter EX and was also used by Ken's Psycho Power-brainwashed counterpart Violent Ken in SNK vs. Capcom: Chaos. This version of the super is a combination of Shippu Jinrai Kyaku and Ken's signature Shoryu Reppa, starting with the multiple kicks of the former and ending in the latter.
The pose Ken takes at the beginning of this final smash is his parry animation from Street Fighter III and appears to form a reference to "Evo Moment #37," a legendary moment in professional fighting game history where during the 2004 Evolution Fighting Game Championship, famous SF player Daigo Umehara, who used Ken faced off against Justin Wong, who played Chun-Li. Daigo's lifebar was down to a mere sliver, but he was able to parry every single hit of Chun-li's Hoyoku Sen super before retaliating successfully with an aerial and crouching kick leading into Shippu Jinrai Kyaku, snatching victory from the jaws of defeat.