The leader of the dragon clan, Ryu Hayabusa — who is also the star of the Ninja Gaiden series — is also back in prime form for DoA 6.
Hayabusa's combo challenge is one of the hardest in the game, which indicates his extremely high power level. But as with all top-tier fighters, he shines only in the hands of very skilled players.
If you can master his Fatal Stun ceiling combo, then you can call yourself the Hayabusa master. Otherwise, just go with the more traditional down-forward move set, where you need to press and hold down-forward with a slight delay and then use H+K.