Howard X Miller, known in Japan and nicknamed in the dub as X (エックス, Ekkusu) is a member of the Society of Light and a Pro League Duelist, ranked higher than Aster Phoenix (in the dub, he is Sartorius' lawyer, and claims he dreamed of being a pastry chef when he was a child). He successfully reduces the cards in Jaden Yuki's Deck to zero (twice), but ironically loses when he's unable to draw due to the effect of the "Neo-Spacian Glow Moss" that Jaden Summoned on X's field, causing him to Deck Out instead of Jaden.