Yu-Gi-Oh! 5D's Season 3 Episode 10

Synchro Solution

The mysterious dueler, known only as Vizor, decides to train Yusei to face Ghost. He starts off by racing him, testing Yusei's ability to handle mach speeds. Once he cleared that, the duel begins, with Vizor managing to summon two Synchro Monsters in his first turn. Before Yusei is able to counterattack, Vizor speeds up to mach-speed, performing an Accel Synchro with his two monsters to form a new one. Yusei responds by summoning Drill Warrior, and powers it up later, though Vizor decides to take direct damage and lose the duel, instead of damaging his monster. The Yliaster, who had been watching the duel, become curious about Vizor's actions.