Not bad but could use improvements

To make the flash a lot more dramatic try zooming into the fight. Like when the black stick freezes time the a close up when he goes for the kill. It can make this flash way more interesting. Keep trying practice makes perfect.

Pretty artistic

I thought the art and animation were handled fairly well. If I had one grievance, it was the representation of dialogue...try a different font, maybe at the bottom center of the screen, so it would seem more like a subtitle. Other than that, make it a longer battle next time and you'll have a pretty great stick figure flash.