One night, when Shark walked down an alleyway, Luna approached him, hiding her identity beneath a cloak.
She soon reveals and introduces herself, and says that Shark can call her an emissary from the moon. Shark replies saying that that looks like something straight out of a fairy-tale, but that he doesn't hate them though. Luna says that she doesn't have any rancor against him, but that she must face him. Then, they begin a Duel.
The Duels ends quickly, with Shark defeating Luna in an OTK. After he wins, Shark asks Luna if she is alright; she is impressed that Shark could Summon 3 Xyz Monsters at once during the Duel, and says that she wasn't wrong. Luna reveals she is a Numbers Hunter whose goal is to eliminate the "Numbers", and says that Shark is the only one who can stop Dr. Faker, and for that he needs the power to do so - a "Number". Shark declines, saying that he was already once possessed by a "Number", and that he cannot do so. However, Luna replies that he knows how terrifying a "Number" can be, and that this is just why it would be okay. She further explains that "Numbers" are mirrors that reflect the hearts of the people, and at that time, his heart was full of darkness, but Yuma and Astral freed him from that darkness. She then gives Shark a mysterious card, and says that that's a new power to protect him.