Luna is a mysterious Numbers Hunter who opposes Dr. Faker and has the ability to negate Kaito's photon abilities. She uses a Moon-themed deck and was the former owner of No. 47: Nightmare Shark before she gave it to Ryoga.
- Defector from Decadence: She used to work for Dr. Faker.
- Hunter of Monsters: Like Kaito, she's also a Number Hunter.
- Lunacy: Her monsters are moon-themed, except for Kachi Kochi Dragon, her Xyz Monster.
- Mysterious Waif: Luna is a mysterious young woman with ties to Dr. Faker who gives Shark a new Number.
- Power Nullifier: Her pendant can nullify Kaito's abilities.
- Zettai Ryouiki: Grade A.
Dr. Faker's Number Hunters
- Artificial Human: He's a kernel of corn given human form
- Anthropomorphic Food: He is a humanoid corn kernel.
- Astonishingly Appropriate Appearance: Imagine a pirate made of corn.
- Cruel and Unusual Death: Explodes into popcorn upon defeat and is eaten by Yuma and friends.
- Trademark Favorite Food: Corn, obviously. He uses a Corn deck. Which leads us to Death by Irony.
- Artificial Human: He is made of electrons.
- Badass Family: His archetype (Hunder) is comprised of a father, a mother, a son and a daughter.
- Cool Bike: His Speed Loader Theme Park attraction.
- Go Out with a Smile: Finally got his wish when Yuma offers his hand before he turned back to electrons.
- Harmful to Touch: Due to his power, nobody could touch him without being slightly electrocuted.
- I Just Want to Have Friends: Being made of electrons, it is difficult for him to make friends since he can't touch anyone without electrocuting them.
- No Mouth: Thunder Spark doesn't have a mouth.
- Our Homunculi Are Different: Thunder Spark is an artificial life-form created from electrons.
- Arson, Murder, and Jaywalking: The three reasons why she duels with Yuma: because she's a Numbers Hunter, because Dr. Faker ordered so, and because Kotori and Cathy stole her clothes.
- Creepy Doll: At first.
- Living Toy: Courtesy of Grandpa Demetto who is a Shout-Out to Pinocchio.
- Elegant Gothic Lolita: Her dress fits.
- Gray Rain of Depression: After she was thrown away.
- HeelFace Turn: Was originally an antagonist but after being defeated, she became friends with Yuma.
- Parental Abandonment: Technically. Cathy "abandoned" her when she outgrew her doll phase.
- Rapunzel Hair: Her hair is almost as long as she is tall.
- Weaksauce Weakness: Not her, but her Number monster is unable to attack female monsters. Yuma accidentally stumbles upon it when he summons his Gagaga Girl, which becomes instrumental to Yuma's victory.
The fourth Numbers Hunter sent to attack Yuma. His deck has a deep-space theme and owns No. 42: Starship Galaxy Tomahawk
- Busman's Vocabulary: His whole speech pattern is based on spaceships and military.
- Cool Starship: His deck, especially his ace, Number 42 Galaxy Tomahawk.
- Going Down with the Ship: Cruelly Invoked by his superior Kyoji before ending his life.
- Stone Wall: How his ace functions: Galaxy Tomahawk possesses no ATK, but has 3000 DEF, along with the ability to call in a deadly air strike.
- You Have Failed Me: Combined with Family-Unfriendly Death, Kyoji performs a penalty game on him after his loss: Kyoji's pet spider bites Eviluder's heart, killing him.
- Zerg Rush: His main strategy: summoning his Number, then calling upon 4 Battle Eagle Tokens with 2000 attack points each, annihilating the opponent in one turn.
The fifth Numbers Hunter to appear to Yuma, Eviluder's commanding officer and also the commander of Dr. Faker's Numbers Hunter army. In the manga, he takes the place of IV for making Shark fall from grace; he tried to steal the deck of a renowned duelist and fails, except Shark takes the blame for him.
He owns No. 70: Deadly Sin, No. 21: Frozen Lady Justice, No. 14: Greedy Sarameya, No. 23: Spirit Knight of the Underworld - Lancelot, No. 35: Ravenous Tarantula, No. 84: Pain Gainer, No. 77: The Seven Sins. Also he was the former owner of No. 28: Titanic Moth and No. 95: Galaxy-Eyes Dark Matter Dragon before giving it to Haruto and Kaito Tenjo respectively.
- Animal Motifs: Spiders.
- Arc Number: Kyoji has two numbers associated with him.
- 8, in companion to his Spiders theme. The total amount of Numbers he has are 8.
- There is also the Number 7, which all his numbers (except Number 23) are divisible by, and 2 of his most iconic Numbers, Number 70 and 77, are tied to this number by representing the Seven Deadly Sins. Their names ( "Deadly Sin" and "The Seven Sins" ) should be already enough of a giveaway.
- Broken Ace: It seems to be the case, as he tells Shark during their Duel that it was literally Hell that made him this way (turned him from a somewhat cheerful friend to a Straw Nihilist) . He told his friend, while trembling, that his beloved little brother, died by his own hand.
- Cain and Abel: Played With: Kyoji did his best to become the Dueling champion to get back with his beloved brother Yuji, from whom he was separated. He succeeds, but notices something unsettling about his brother, to discover finally it was an impostor who killed the real Yuji to take his place and make money off of the Duel champion. Kyoji tried murdering him to avenge his brother, but couldn't go with it due to the unsettling similarity between the imposter and his brother. Then E'rah appeared...
- Dark and Troubled Past: His parents died in an airplane crash, causing him to be sent to an orphanage while his little brother Yuji was adopted. Wanting to see his brother again, he tried to become the Duel Champion. He succeeded but an incident he was responsible for led to his friend Shark's fall from grace. Still Kyoji managed to be reunited with his sibling, only to realize that something was wrong with his brother and when he confronted him about it, he learned that "Yuji" was an imposter who killed the real one, causing him to strangle said imposter.
- Expy: Of IV - they both have a complicated relationship with Shark - including having been involved with him in a cheating scandal that resulted in Shark's disqualification - and a rather smug personality.
- He also bears a notable resemblance to Yusuke Fujiwara - they both have tragic backstories involving loss of family members that allowed a force of darkness to take over them, resulting in them being the main antagonist up until the final duel, where the force possessing them leaves their body and takes over the duel.
- Hope Is Scary: He tells Shark he will teach him how "Hope and Despair are two sides of the same coin: the more hope one has, the deeper their despair will be." considering what he once did, it's not hard to understand why he thinks that way.
- Lucky Seven: All his known numbers (14, 21, 35, 70, 77, and 84) are divisible by 7. The only one to avoid this is Number 23.
- The Magic Poker Equation: Averted like with power of ZEXAL: Usually, Number Cards are blank and take their definitive forms when the "victim" touches one, based on that person's secret desires, and takes over them, making their desires uncontrollable. For Kyoji, it is different: the Numbers he possess are all blank, and only take form whenever he summons them during a duel, and their effects become just what he needs in order to get out of a tight spot. According to him, it is because his one and only desire is "a wish as insubstantial as a single spider's web drifting on the wind". See Straw Nihilist below for more info.
- Mythology Gag:
- Kyoji's name is similar to Kouji Nagumo from the first anime series. Both characters also have a spider motif.
- He also used a penalty game called Mind Crush on Eviluder, although it was different from Yami Yugi's Mind Crush.
- Sibling Yin-Yang: Although they are not siblings, he is the Light to Shark's shadow.
- Straw Nihilist: Kyoji's true colors are revealed to Mr. Heartland at the end of their duel. He knows all about Mr. Heartland's heinous crimes, but he considers the true sin committed by Heartland stopping the attacks on the Astral World to protect Earth, which will be destroyed in the process. According to him, the world deserves destruction, and existence is meaningless.
- Unhand Them, Villain!: In Rank 26, when Yuma asks him to let Haruto go while they're both standing at the top of a tall building. You get no points for guessing what he does next (though he does give the mercy of holding Haruto up by a thread rather than outright dropping him).
Another Numbers Hunter in service to Kyoji. Owns No. 72: Line Monster Chariot's Rook.
The Third Numbers Hunter that serves Kyoji Yagumo. Was the holder of No. 13: Cain's Devil, No. 31: Abel's Devil, and No. 48: Shadow Lich.
- Kill and Replace: The real Yuji was killed and impersonated by another kid wanting to be rich from Kyoji's success.
- Parental Abandonment: His parents were killed in a plane crash. But while his older brother got sent to an orphanage, Yuji was adopted by another family who abandoned him after losing all their money.
- Boobs of Steel: The most powerful female character in the franchise and easily the bustiest.
- The Corrupter: This is her role as a Hope Crusher.
- Her corruption of Kyoji causes him to kill his imposter younger brother and become a Straw Nihilist.
- She also corrupted Dr. Faker, albeit more indirectly, by marking Haruto with a curse that leaves him fragile since birth, resulting in Dr. Faker resorting to drastic measures, culminating his waging attacks on the Astral world, in his desperate attempts to cure Haruto.
- Distaff Counterpart: To Don Thousand, being the enemy Astral was sent to defeat in their respective continuity.
- Evil Counterpart: Some of her cards allows her to summon E'Rah monsters, dark counterparts of her opponents' monsters.
- Greater-Scope Villain: Of the ZEXAL manga.
- Hope Crusher: She is stated to be able to scent hope and then crush it.
- My Death Is Only The Beginning: Her monsters, that is - Strain Nuke and Strain Bomb only activate their effects if they're themselves destroyed. They then become parasites on Xyz monsters, spawning E'Rah monsters.
- Physical God: She's one of Despair, contrasting against Hope.
- The Woman Behind the Man: Once again, to Kyoji. She's the one who gave him his numbers and abilities.