Reginald Kastle's Decks

Reginald plays an Xyz WATER Deck consisting of monstrous looking sea creatures such as various races of sharks and arthropods. His nickname is "Shark" and is derived from his Deck theme and his previous brutal nature.

Pre-World Duel Carnival
Shark utilizes a Burn strategy in order to gain an early advantage through cards such as "Submersible Carrier Aero Shark" and "Booming Urchin", with a focus on using Level 3 monsters to Xyz Summon Rank 3 Xyz Monsters. After losing to Yuma he modified his Deck to counter the "Numbers" by negating their effects with his ace monster "Black Ray Lancer". as well as cards to take control of them. Reginald's Deck also sports a few cards that destroy Spell and Trap Cards such as "Mystical Space Typhoon" and "Skull Kraken".

World Duel Carnival Preliminaries
During the World Duel Carnival preliminaries, Shark continues to use similar strategies as he did previously, with a focus on Rank 3 Xyz Monsters, also adding Level manipulation cards like "Falling Current" and "Hammer Shark". He also utilizes more cards focused on negation such as "Plate Salvage" and "Sea King's Verdict".

World Duel Carnival Finals
After acquiring "Number 32: Shark Drake", Shark's Deck became more focused around Level 4 Monster Cards and reducing the amount of Overlay Units required for Xyz Summons such as "Bubble Bringer" and "Xyz Remora". After obtaining "Number C32: Shark Drake Veiss" through Chaos Xyz Evolution, Shark also began to use more members of the "Shark" archetype.

Yu-Gi-Oh! ZEXAL II
Shark continues to use an Xyz WATER Deck. His Deck has become even more flexible in terms of his use of Xyz Summoning, now ranging from Rank 3 to Rank 5. In addition, he also uses a large quantity of cards to swarm monsters to Xyz Summon such as "Three Slice", "Panther Shark" and "Eagle Shark". His Deck also features a range of new "Shark" monsters as well as other aquatic fauna like "Big Whale" and "Starfish".

Deck
Shark's manga Deck is similar to his anime Deck, but with an increased focus on Xyz Summoning using the effects of cards such as "Chain Summon" and "Bahamut Shark", which is his ace monster.

Collected Numbers
So far, Shark has obtained 2 "Numbers" card, disregarding "Number 17: Leviathan Dragon", which was absorbed by Astral.