Yu-Gi-Oh! 5D's (2008)

Episode Overview

The Fortune Cup kicks off with Krieger facing off against Leo, who's secretly filling in for his sister Luna since she refused to compete. Krieger's aircraft machine monsters leave Leo's Morphtronics struggling to keep up. Off to the side, Goodwin's scientist Zigzix tests his new invention—a device built to track Signer activity. It goes off for Luna, but stays silent for Leo. Leo ultimately loses the match, and Zigzix realizes Luna was watching from the stands the whole time, exposing the swap.