User blog comment:Xilinoc/Ch. 585 - The Headless Star 4/@comment-24384892-20140618125247/@comment-24913480-20140618130526

Kensei (Shuhei's captain) already confirmed that he has indeed a bankai. He was training him before the second invasion. But he's still just a lieutenant so I don't expect his bankai to be overpowered.