i think its senbonzakura or suzumebachi
they say it Genryuusai Yamato-the old man
i agree with soifang_fan that senbonzakura is the most powerful have u seen it the only one to ever not get hit by it is icigo
Yeah ichigo's just a bad-a** though
it kills in two hits why wouldn't
that be powerful?
Ryuujin jakka, and Kyouten Kakuso? Kyoraku's shikai because it's so impredictable.
Oh and KYOKA SUIGETSU!
Senbonzakura it's even stronger now(in the manga) but the powers of true zangetsu is not known yet.
I think its Katen Kyoukotsu