Jack attacked and destroyed "Junk Warrior" with "Mad Archfiend" (Yusei: 0 Life Points), defeating Yusei.
Jack told Yusei that one cannot win a Duel with Monster, Spell or Trap Cards alone, only by combining them. He gestured to his heart as he said that all one needed to amass themself in victory was right there. At the time, Yusei did not understand what he meant.
Yusei repeated Jack's words after he defeatedLenny, saying that a friend thought him it. He admitted to not knowing what it meant before, but said he then knew that it's the soul of a duelist that believes in every card that was necessary to win.