Chu readies an attack against Yusuke in Ep. 31 of the series, during their bout in the Dark Tournament. I love the colors and the BG that the cel came with suits it quite well. It's a shame that a lot of the cel seems to have been lost in the actual production, as you can see in the screencap.

The two cels that follow mine can also be found in RS galleries.

SPIRIT GUN has the A13.

Dark Water Dragon has the A14.