Kageoni

is a technique used by Shunsui Kyōraku's Zanpakutō, Katen Kyōkotsu.

Description
The rule of this game is that whoever gets their shadow stepped on "loses. The game itself allows competitors to manipulate shadows to their advantage. For example, Shunsui has demonstrated the ability to hide himself in shadows by using this technique, and he can also control the shadows and use them to attack an opponent by attacking the shadow they are currently standing upon.