Yu-Gi-Oh! ZEXAL - Episode 121

'''The Shark Knight Awakens! The Revenge Match of the Raging Seas: Nasch vs Vector''' is the one hundred and twenty-first episode in the Yu-Gi-Oh! ZEXAL anime.

Having lost the Duel against the past Vector, Reginald Kastle regains the memory of being killed. Shaking in anger and humiliation, he challenges Vector to a revenge grudge match! However, Vector, who now wields the power of Don Thousand, has become so strong he virtually outclasses Shark. While he endures the brutal assault of Vector's attacks, Shark reawakens the power of Nasch, and unleashes a counter attack using his Over-Hundred Number!