Shinkuro from Kure-nai, on seeing his mentor/boss get stabbed, which triggers him into fully releasing the assassins blade surgically placed inside of his arm. He goes into a mindless killing rage, using previously unseen insane skills, wiping out the guy who did it in under a second. After 11 episodes of him looking like a pathetically incompetent fighter, this was pure awesome...
And, earlier in the same episode, we have his mentor, Benika, pulling off a crazy Car Fu scene that ends with her plowing into the antagonist's mansion with her car. But the best part was the exchange with the antagonist that shortly followed:
Renjou: Do you know why I'm in a bad mood?
Benika: Because it's forbidden to park in the Inner Sanctuary?