supreme_king_(yu-gi-oh!_gx)
The wielder of "The Gentle Darkness" and the alternate, darker_personality of Yuki Judai that possessed him until he was defeated, serving as the final antagonist of the third season in the Yu-Gi-Oh! GX anime.
The Supreme King plays an Evil Hero deck, which are vile incarnations of Juudai's Elemental Heroes.
Not to be confused with Supreme King Z-ARC from Yu-Gi-Oh! ARC-V.