As a rendition of what Shusui Kyoraku’s Bankai would look like came from, Deviant Art Artists, Arrancarfigther. We’ve never seen Shunsui ever open his Bankai, but we can certainly predict what his Bankai would look.

“As far as appearance goes I’m well aware that it not as different as other Bankai users are, but when considering Byakuya or Gin’s Bankai’s it’s not that hard to believe (As both of theirs also resembles their Shikai, but stronger)

Kyoraku’s Bankia has two main abilities, the first is an advanced version of his Shikai’s ability “Kageoni” he is able to stab his sword into the ground, and from beneath his opponent erupts a massive cluster of large shadow blades similar in appearance to the Groundspike Devastator ability from the game Prototype.

Now, normally he would have to stab his sword into the shadows for this to work, however when he uses Bankai dark storm clouds cover the sky, blotting out the sun and engulfing the battlefield with darkness.

The second main ability of his Bankai is even more powerful. He releases wind energy from his Zanpakuto which forms a massive dark tornado/twister. Both Kyoraku and his opponent(s) are then sucked into the Tornado and trapped within until either the battle is over or Kyoraku is killed. While in the Tornado advanced versions of Bushogoma, Kageoni and Irooni can be used.” From Image Description.

Hopefully we will see his Bankai in future episodes, when it releases, I’m sure I’ll be here to tell you about it. So keep in touch.