Exodia the Forbidden One
From UnAnything Wiki
Exodia the Forbidden One is probably the most overpowered guy in the Yu-Gi-Oh! game. Lucily, he can only use his full power when he has access to all his arms and legs and he doesn't by default. When you have him, along with his limbs, on your side of the field, you win the game. He is partly responsible for the decline in the length of Yu-Gi-Oh! matches.