The third season of Yu-Gi-Oh! featured the characters trapped in a virtual world created by an annoying aquamarine-haired boy named Noah. While inside the world, Yugi and company were forced to battle Kaiba Corp's Big Five under Noah's new rules. The main gimmick was that each player needed a Deck Master, a monster from their deck with unique abilities.
It existed outside of the field unless the player summoned it into the game. If the Deck Master was destroyed, the player automatically lost the game. Deck Masters provided an exciting shift to the usual duel dynamic that audiences knew and loved. And while some monsters were definitely gifted with amazing abilities, others got the short end of the stick and had to settle for mediocre powers.
Worst: Nightmare Penguin
The duel between Téa and Crump, KaibaCorp's former CFO, was relatively boring and low-stakes. It's comprehensible since Téa wasn't a duelist and her abilities didn't compare to Yugi, Joey, and Kaiba's. And Crump too proved to be a basic duelist, starting with his Deck Master.
Nightmare Penguin allows all face-up water monsters the player controls, to gain 200 ATK points. It's a very simple ability, and its restriction makes it even more situational. Crump's deck was composed mainly of water monsters, but still, 200 ATK points is a very low amount to actually add up to anything of real value.
Best: Deepsea Warrior
Kaiba-Corp's former VP, Gansley, was Yugi's first opponent in the virtual world and proved to be a rather capable foe. He took the form of the Deepsea Warrior, which also acted as his Deck Master.
A decent monster in and of itself, Deepsea Warrior's ability really took it to the next level. It allowed the player to negate any attack from the opponent by tributing two monsters and then inflicted damage equal to the attacking monster's attack. It's a truly amazing ability, one that gave Yugi considerable trouble to overcome.
Worst: Goddess With The Third Eye
Like Téa, Serenity wasn't a duelist either. Unlike Téa, however, Serenity had to face an opponent who was actually tough. For her Deck Master, she chose the Goddess With The Third Eye, a card on the weaker end when it came to ATK and DEF points.
Its ability was no prize either, basically acting as any regular Polymerization card. It allowed the player to send Fusion Material Monsters to the Graveyard, and then Special Summon the Fusion Monster. The FMM needed to be either on the field or the player's hand, making the ability even more restrictive.
Best: Kuriboh
A card long mistreated and disrespected, Kuriboh proved its worth time and again. Yugi had a soft spot for the ball of fur, and used it very successfully several times, usually pairing it with the Multiply card.
As a Deck Master, Kuriboh allowed the player to negate any kind of damage from an opponent's card, be it a monster, a magic card, or a trap. The effect was limited to just once per turn, but it was still highly useful, proving just how valuable Kuriboh could really be.
Worst: Jinzo
Jinzo is an incredibly powerful and rare card. It not only had a very high attack of 2400, but it also had a respectable defense of 1500. However, what truly made Jinzo special was its formidable ability, which allowed it to negate the effect of a trap card effect on the field.
This ability, however, was the same one it had as a Deck Master. Unlike Kuriboh, whose effect as a monster was enhanced when acting as Deck Master, Jinzo's had no significant increases or alterations. This meant that choosing Jinzo as DM was a waste since its ability basically became redundant.
Best: Robotic Knight
An average monster by itself, Robotic Knight became a real threat when used as a Deck Master. By discarding any number of Machine-Type monsters, the player could inflict direct damage to the opponent, equal to the amount of cards discarded times 500.
Used as Deck Master by Nezbitt, KaibaCorp's former CTO, who ran a machine deck, Robotic Knight was a deadly weapon. Nezbitt was the only one of the Big Five who actually won part of his duels. He fought Doug, Serenity, and Tristan at the same time, and even managed to beat the latter.
Worst: Flame Swordsman
Joey's favorite card in the game was a logical choice to act as his Deck Master. Just like the monster itself, the ability wasn't entirely bad. However, compared to the rest of the Deck Masters, it definitely fell in the "worst" category.
Flame Swordsman allowed the player to decrease its attack points in multiples of 100, and add them to any monster of the player's choice. And considering that Flame Swordsman had an 1800 ATK, the ability soon became obsolete. In his duel against Johnson, Joey didn't think ahead and quickly used and practically exhausted the card's points, confirming this Deck Master's problems.
Best: Judge Man
Speaking of Joey, his opponent had one of the absolute best Deck Masters in the game. Johnson, the former lawyer for KaibaCorp, took on the form of Judge Man and gave Joey some serious trouble.
By paying 1000 life points, Judge Man allowed the player to destroy all the opponent's monsters and inflict damage equal to the number of monsters destroyed times 500. Johnson could then attack Joey's life points directly, inflicting even more damage in a single turn. It's a truly terrifying ability, one that could easily win a game if used properly.
Worst: Dark Magician Girl
Dark Magician's ability could be either good or bad, depending on how much luck the player had. It allowed the player to reveal one card on top of their deck, for each monster he or she had in his or her graveyard.
If the player had no monsters in the graveyard, the ability became useless. Same case if the cards atop the player's deck were not particularly useful, or if the monsters were weak. The ability relied on pure luck that the next card in line will be the one that turned the game around. And comparing it to the other Deck Masters, this one can't help but feel underwhelming.
Best: Shinato's Ark/Shinato, King Of A Higher Plane
Noah's Deck Master, used in his final duel against Kaiba and eventually Yugi, Shinato's Ark was absurdly overpowered. In its first form, the Ark, it could be equipped with monsters from the graveyard. These could then be used as cannon fodder to protect the player from attacks, or as tributes to gain 500 life points for each one.
If destroyed in battle, the Arc allowed the summoning of Shinato, King of a Higher Plane. This new monster had even more insane abilities. It allowed the player to increase his or her life points whenever the opponent's were decreased. If summoned into the field and it destroyed any monster in defense position, it allowed the player to halve the opponent's life points.
These tandems caused more than enough problems for Kaiba and Yugi, and with reason. Their multitude of abilities made them, by far, the best Deck Masters in the game.