Depending on how absurdly cool your martial arts style is -- are you Jackie Chan, or are you doing absurd stuff like in the Swordsman movies? -- you can justify some fairly out-there powers:
Paralyze (alt-save:Fortitude): A Chi-strike on pressure points
Stun: A blast of Chi energy
Autofire Extra: Dozens of strikes over the space of a few seconds
Penetrating Extra: Focusing your Chi to strike with the power to punch through a solid wall
Groundstrike (Trip, flawed to Touch, with the Area(Cone) and Knockback Extras): Staple of the wuxia genre, with the guy doing a blast of power into the ground to blast people back.
Yes, all of that stuff is pretty out there, but then, so is an alien flying around lifting trains and shooting lasers out of his eyes.

If you're going for more Jackie Chan, then I'd suggest buying Strike up to +5 and giving it the Autofire extra (twice), along with Improved Critical a few times -- you're within the realm of possibility for human power, and you won't be able to hurt someone with Impervious, but you'll be useful in a fight, especially with the feats others have mentioned. You may want to take Penetrating Strike as an Alternate power of your Autofire strike to simulate focusing your power for a really big strike. You still won't be punching through walls -- at least, not brick ones. You could take down drywall without any trouble, though.
