What are Byakuya's Gokei, Senkei and Shuukei?


In addition to his bankai, Byakuya is observed using three techniques:

  * Gokei 

> I think it was in battle with Hitsugaya's Reigai, though I'm not sure

  * Senkei 

> while fighting Ichigo at Rukia's execution

  * Shūkei 

> in the same fight as above

Not only is this the largest number of Zanpakutō abilities that we have seen
in one sword (I think), but each one of them seems more powerful than the last
(and more powerful than his bankai!).

So what exactly are those three techniques? Why is Byakuya the only one in
_Bleach_ to have so many different techniques contained in his Zanpakutō?




They are various forms of his bankai, achieved by arranging the blades in
different patterns. His bankai is versatile by nature (being composed of
countless tiny blade fragments), and affords him several forms, with varying
combination of attack and defense.

Whether a bankai can have multiple forms depends on its nature. Hitsugaya
Toshiro and Abarai Renji _could_ also achieve multiple bankai forms with
practice/training. The former could mold Hyorinmaru's ice into various forms
(like [fairy-tail](/questions/tagged/fairy-tail "show questions tagged 'fairy-
tail'")'s Gray), while the latter could rearrange Zabimaru's segments.
Shinigami such as Komamura, Tousen, or Soifon would likely not have multiple
bankai forms due to the nature of their bankai.

By the way, Byakuya is no longer the only known shinigami with multiple bankai
forms

> as Yamamoto Shigekuni's bankai has been revealed.

Also, Byakuya's sister, Rukia, has _shikai_ with multiple forms:

> Tsukishiro, Hakuren, Shirafune, and Juhaku




They are various forms of his bankai, achieved by arranging the blades in
different patterns. His bankai is versatile by nature (being composed of
countless tiny blade fragments), and affords him several forms, with varying
combination of attack and defense.

Whether a bankai can have multiple forms depends on its nature. Hitsugaya
Toshiro and Abarai Renji _could_ also achieve multiple bankai forms with
practice/training. The former could mold Hyorinmaru's ice into various forms
(like [fairy-tail](/questions/tagged/fairy-tail "show questions tagged 'fairy-
tail'")'s Gray), while the latter could rearrange Zabimaru's segments.
Shinigami such as Komamura, Tousen, or Soifon would likely not have multiple
bankai forms due to the nature of their bankai.

By the way, Byakuya is no longer the only known shinigami with multiple bankai
forms

> as Yamamoto Shigekuni's bankai has been revealed.

Also, Byakuya's sister, Rukia, has _shikai_ with multiple forms:

> Tsukishiro, Hakuren, Shirafune, and Juhaku

