Tragoedia

Tragoedia is the main antagonist of the Yu-Gi-Oh! GX manga. During the time of Pharaoh Atem, Tragoedia was the ka of a criminal, and Winged Kuriboh was his opposite number, the ba. At the criminal's trial, he was convicted, and Tragoedia was sealed in a tablet and the tablet smashed. He awoke centuries later as a lingering poltergeist, and soon gained the American branch of Duel Academy under his control. Using his agents, in particular David Rabb and Reggie MacKenzie, he plans to acquire Duel Spirits and exact his revenge. (Source: Yu-Gi-Oh! Wikia)