Shunsui

Shunsui's Bankai has four phases.

Shunsui likely kept Nanao close to protect her, his only family.

Shunsui's statement on change is powerful and fits well with his easygoing nature.

How else would anyone have known that Mayuri's face was decorated blue-gold, that Ulquiorra's Cero Oscuras was a pulsating greenish-black, or that Kyouraku Shunsui's haori was a gorgeous pink?

They are both parts of the same soul, which makes it all the more miserable when Lilynette "dies" during their final battle against the future Captain-Commander, Shunsui.