Quattro

IV is a character appearing in the Yu-Gi-Oh! ZEXAL anime. He is a participant in the World Duel Carnival and the Champion of Asia. He is the one responsible for Reginald Kastle's sister's accident which resulted in her being hospitalized, and is the most brutal out of the Tron Family.

Appearance
IV has a scar on the right side of this face. He and his brothers (III & V) have a crest on their bodies; IV´s crest is purple and on his right hand. He has a Duel Gazer-like pattern that appears around his eye similar to Kite Tenjo (although he has worn a regular Duel Gazer in the past).

He has large, spiky dark red and yellow hair and wears a long flowing coat with white pants, boots and a shirt which all feature a curly, high-class pattern. IV's D-Pad has the appearance of a red blade which separates into three sections. He highly resembles Takuto Tsunashi from the anime Star Driver.

Personality
IV is a sadistic and malevolent Duelist who wants to make his opponents suffer, with what he calls his "fan service", in order to win. When in the presence of his fans, his personality becomes a facade as he hides his true nature and becomes a "noble" and "well-mannered" person. He sees his fans as bad Duelists and challenges them as his "fan service". When he Duels, he initially praises their skills and lets them think they have the upper hand. When his opponents fall into his trap he shows his real self and defeats them cruelly, going so as far as to keep attacking his opponents even if they have no Life Points and claiming his "fan service" must continue. He even went so far as to show a child getting tortured on a television screen to the others for his pleasure.

During his Tag-Team Duel, it is shown that IV desperately seeks to make his opponents suffer by any means possible, and feels otherwise frustrated and angered when his "fan service" is ruined. He also seems to justify this sadistic behavior because of what the Tron Family had "suffered", hinting a more painful side of him.

IV argues a lot with his brothers, showcasing that he is willing to let his personality get in the way of their true goal and doesn't always follow Tron's orders, unlike III and V. He also seems to have a slight fear of V, shown when he got intimidated after V got mad at him for talking back to Tron. Despite this, after III was brutally defeated by Kite Tenjo in their Tag-Team Duel, IV showed concern for his defeated brother, proving that he does care for his siblings.

As a child, he wasn't as brutal as he is now, but he had a tendency to tease III like normal brothers do and kept taking his cards. He also had a respect for V already back then as he returned III's cards when V told him to.

When pretending to be kind, he also refers to himself using the pronoun "boku", but switches his pronoun to his usual "ore" after showing his true self.

Etymology
IV's name is the Roman numeral for four. The number of "Number 15: Gimmick Puppet - Giant Killer" is a pun on IV's own name, since "I" alone is the roman numeral "one" and "V" is the numeral "five", forming "15". IV's second Number, "Number 40: Gimmick Puppet - Heaven's Strings" is based on the true meaning of IV's name, instead of breaking it down.

Childhood
In his younger days, IV along with his brothers and their father lived a happy life with their dog, where he was innocent and happy. One winter night, their father gave III a Duel Monsters card - "OOPArts Aztec Mask Golem", which III showed to IV. IV was jealous because only III received a card and tried to take "Mask Golem" from III. V told them to stop or their father will scold them and then promises to teach both of them how to Duel. An unknown event caused by Dr. Faker caused the family to become focused on obtaining revenge on him.

National Duel Circuit
IV was a participant in the National Duel Circuit who faced Reginald Kastle in the finals. He set Reginald up to be disqualified by planting his Deck on top of a pot, so that it would fall and end up scattered on the floor in the break room. That way, IV ensured Reginald would see it, though Reginald himself was unaware of that until IV himself told him later.

World Duel Carnival
IV reappeared to Reginald and lured him to a building in construction by throwing a "Mirror Force" card at him. Reginald asked why he did that, and IV responded that it was just a form of greeting before the World Duel Carnival. Reginald responded that he won't participate in the tournament, and IV asked if Reginald is still influenced by what happened at the Duel Circuit. He revealed that he knows about Reginald's sister, who got into an accident. He told Reginald that he intentionally got him disqualified, and even implied that he caused the accident that injured Reginald's sister. Reginald was enraged by this, and IV taunted him, saying that on that day, he became the Duel Champion of the Far East. IV threw a Heart Piece to Reginald, telling him to try to defeat him in the World Duel Carnival.

After that IV approached Tron, who was watching cartoons. He told him that he did as he was ordered - Reginald will participate in the WDC. IV asked why Tron wanted Reginald to enter the World Duel Carnival as he already has given up on being a Duelist. Tron responded that he is needed for when all the "Numbers" cards are collected. IV stated that he doesn't care as long as he can drag Reginald into hell again.

During the morning of the second day of the World Duel Carnival, IV studied the opponents which are available within the WDC via sheets, which contain information on them and their signature cards. Here, he throws cards at them in order to choose an opponent. Seeing this, V commented that he is too brash and should calm down if he wants their plan to succeed. Angered by V challenging his ethics, IV challenged him but is quickly shot down by V being reinforced by his brothers, III and Tron.

Later on in the day, IV agreed to meet Bronk Stone and Caswell in order to sign their Duel Disks, but had an ulterior motive to entice them to a hidden location so he can Duel them with his "Numbers" and reveal his real personality without allowing the public to see him as his true self. He suggested a Battle Royal, which they agreed to. During the Duel, he allowed them to get the upper-hand by Summoning their aces, "Vaccingale" and "Tinplate Archduke". This was all a ploy as he lured them into Xyz Summoning so he could perform two One Turn Kills with his "Number 15: Gimmick Puppet - Giant Killer" and "Gimmick Puppet - Baby Face". His personality changed at this moment from the friendly and noble champion of the East, to a merciless and evil person who enjoyed the pain of others, laughing when his monster hurt Bronk and Caswell. After the Duel, Reginald arrived on his motorbike, making IV smirk.

IV intended to Duel Reginald then and there, but was stopped when III snared Reginald with a Duel Anchor, telling IV that Tron's orders are absolute - III is to Duel Reginald first. IV revealed that he already had a full Heart Piece, and told Reginald he'll be waiting in the finals and then departed.

After V brings Hart Tenjo to an abandoned gallery, IV watches as Tron begins his ritual in order to transfer all of Hart's powers and memories to himself. As the ritual continued, Hart began to feel more and more pain, which amused IV as he watched intently. After Yuma Tsukumo and Kite Tenjo break into the Gallery, V sends IV and III to stop them from reaching the ritual in order for it to complete. They then appear before the pair, attaching their Duel Anchors to them, initiating a Tag-Team Duel.

As the Duel began, IV instantly targeted Kite as he sees him as the bigger threat. When Yuma Summoned "Number 39: Utopia", IV and III instantly know that they have to win this Duel rather than merely stall for Tron's ritual to finish. After Yuma Summoned "Utopia", IV began to target him, destroying "Utopia" straight after it was Summoned via "Number 15: Gimmick Puppet - Giant Killer". After seeing that Yuma and Kite were beginning to work together, IV decided to anger Kite to break those bonds by showing him a video of Hart being tortured through Tron's ritual. Angered by this, Kite continued to damage Yuma through "Photon Pressure World" in an attempt to rush the Duel and beat them as soon as possible. This however was quickly stopped as IV and III had a strategy to stop Kite's "Galaxy-Eyes Photon Dragon" through "Stonehenge Shield", to which III's "Number", "Number 33: OOPArts Super Weapon - Machu Mach", inflicts 3000 points of damage to Kite.

As the Duel continued, Yuma constantly kept intercepting IV's and III's attempts at defeating Kite, causing IV to get extremely angry with Yuma. Yuma managed to Summon his "Number C39: Utopia Ray" and defeated IV's ace, but IV struck back by Xyz Summoning his other "Number" card, "Number 40: Gimmick Puppet - Heaven's Strings". Despite this, Kite managed to Summon "Neo Galaxy-Eyes Photon Dragon" and defeat the brothers in one attack. After the Duel ended, Kite tries to steal IV's soul and "Numbers" using Photon Hand, but was unable to as IV's crest protected him. He vowed to get revenge on Kite and Yuma and departed with III and Tron.

After Yuma and Astral defeated III, resulting in him falling unconscious, IV implored that Tron give him new powers so he could defeat Yuma. Tron responded that he's disappointed in both III and IV. He wanted results and if III and IV can't give him that, he'll use Shark instead. This angered IV, who proceeded to confront Shark at the World Duel Carnival Finals party.

Accomplishments
When Caswell shows IV's Duelist profile, he is revealed to have won the following tournaments:
 * Asia Duelist Championship (9 wins, 0 losses, and 4892.9 points)
 * Mini Surf Expert Match (5 wins, 0 losses, and 573.4 points)
 * T.F.E. Tournament (6 wins, 0 losses, and 949.1 points)

He is also known to have won the National Duel Circuit in the past.

Gimmick Puppet
IV plays a "Gimmick Puppet" Deck, consisting of puppet-like monsters and a OTK strategy using the power of his "Number 15: Gimmick Puppet - Giant Killer", combined with the effect of "Gimmick Puppet - Baby Face". Besides the OTK, he also possesses cards that are able to destroy enemy monsters and inflict massive damage, such as his two "Number" cards. If his key card is destroyed, he resorts to using his "Number 40: Gimmick Puppet - Heaven's Strings". In addition, he utilizes several cards to quickly gather Level 8 Xyz Materials for his "Numbers" such as "Gimmick Box" and "Gimmick Puppet - Necro Doll".

Gravekeeper's
IV used to play a "Gravekeeper's" Deck, based on the cards seen when his Deck "fell" on the floor during the Nationals.

Obtained Numbers
IV was shown to have obtained at least 9 "Number" cards around the time when he Dueled Bronk and Caswell.