Pegasus had already shown in his duel with Seto Kaiba and early in his duel with Yugi that he possessed cards that no one else had that could devastate both of them. However, it’s his duel with Yugi where Pegasus reveals Relinquished, a Ritual Monster that can not only absorb a monster from his opponent, but also use it as a buffer. Any attack on Relinquished would result in the opponent’s monster being destroyed as well as some damage done to the opponent’s life points, something Yugi learns the hard way. It also serves as the critical component to the Fusion Monster Thousand Eyes Restrict, which has the same abilities as Relinquished in addition to locking the opponent’s monsters in their current battle positions. With Pegaus being the final opponent in the 1st season, Relinquished definitely serves well as a “Final Boss” so to speak, and it takes some ingenuity and a little luck from Yugi in order to defeat it.

The card that best sums up Joey Wheeler’s deck during the Duelist Kingdom arc, Time Wizard is the ultimate gamble monster. With very little attack and defense, Time Wizard has only one thing going for it: it’s “Time Roulette” effect, where the result could either result in devastating your opponent or self-destructing and blowing up in your face. Joey is able to successfully use it against Mai by aging her Harpie Ladies and getting Thousand Dragon as well as against Rex by aging his Red Eyes Black Dragon into dust. However, he does suffer some drawbacks against Bonz (where it self-destructs) and Yugi (his Dark Magician ended up transforming into Dark Sage). Still, either way, Time Wizard can be a game changer, especially if it pulls through.

Introduced as the rarest card in Espa Roba’s deck, Jinzo is an example of a powerful monster with a powerful ability to boot. With 2400 ATK as well as the ability to negate and destroy Trap cards, Jinzo is not easy to get rid of if you rely on those types of cards. Jinzo ends up becoming a key part of Joey’s deck in his duels in the Battle City arc as well as a nuisance for Seto in his duel with Leichter during the Virtual World arc. A solid monster to contend with, Jinzo had an impact almost every time he was played.

Another hidden staple of Joey’s deck in the Duelist Kingdom arc, Copycat is also a weak monster with a devastating ability. Seemingly activated as a spell card despite being a monster, Copycat copies the abilities of any card that’s been used previously in the duel. Even though this card’s appearances are brief, Joey uses this card successfully every time he attempts to use it. In the duel with the Paradox brothers, Joey successfully copies Riryoku in order to make Black Skull Dragon strong enough to defeat the Gate Guardian. In his duel with Bandit Keith, Joey successfully copies Magic Metal Force to help create Red Eyes Black Metal Dragon. Finally, in his duel with Yugi, Joey copies Polymerization to summon Black Skull Dragon. Not a card you might expect, but certainly another game changer.

A monster card seen throughout the series as well as Yugi’s favorite card, Dark Magician is pretty effective to say the least. With 2500 ATK and 2100 DEF, Dark Magician is definitely among the elite class of monsters we get introduced to in the Duelist Kingdom arc. However, what makes this monster card so effective for Yugi is his combining it with other cards in his deck. Multiple times we watch Yugi use Dark Magician in conjunction with Magical Hats, Spellbinding Circle, Mystic Box, and as a tribute for the Magician of Black Chaos and Dark Paladin. Not many monsters have that versatility, and Yugi certainly knows how to bring the best from a strong monster card with no special ability.

One of the defining monsters of the series, the Blue Eyes White Dragon is first introduced as being the strongest individual monster in the game. Only 4 were known to exist, with 3 of them belonging to Seto Kaiba, the world’s best duelist, and 1 belonging to Yugi’s grandpa. As a result, players highly regarded the card a fair amount. It’s pretty clear in Yugi’s duel with both Kaiba and Kaiba’s doppelganger that just 1 Blue Eyes White Dragon is enough to take out your opponent’s best cards, much less 3. Kaiba even brings out the Blue Eyes Ultimate Dragon, the fusion of all 3 Blue Eyes White Dragons, to raise the stakes even higher. Not to mention the Blue Eyes Toon Dragon Pegasus creates. Regardless, even though powerful fusion monsters and even rarer monsters show up, Blue Eyes White Dragon is still such a recognizable name and holds a powerful impact.

The first of the 3 God Cards introduced in the series, Obelisk the Tormentor is the God card used by Seto Kaiba in the Battle City arc. With 4000 ATK and DEF as well as the ability to tribute a monster to gain infinite attack or destroy an opponent’s monsters, there’s no question that overpowered is just an understatement. We see a taste of what it can do by Seto in the Battle Simulator after Ishizu gives it to him, and we also get to see Kaiba use it in his duels with both Ishizu in the quarterfinals and Yami Yugi in the semis of the Battle City Tournament, utilizing it in different ways. We also get to see Yugi summon it against Marik in the finals. Almost certainly a guaranteed game winner, Obelisk the Tormentor would be a must for any duelist’s deck in the anime.

The second of the 3 God Cards introduced, Slipher the Sky Dragon comes up in the Battle City arc against Yugi as he is dueling Strings, one of Marik’s Rare Hunters. In that duel, we learn of Slipher’s abilities: 1000 ATK for every card in the player’s hand as well as an automatic 2000 ATK or DEF drop to a monster’s ATK or DEF depending on the position they were summoned in. These abilities combined with the unique Revival Jam strategy used by Strings almost defeats Yugi, but he is able to find a way to win. Afterwards, we see Yugi use Slipher himself in his semi-final duel with Kaiba against Obelisk the Tormentor and in the finals against Yami Marik. Definitely not a card to underestimate by any means.

The third of the 3 God cards in the series, the Winged Dragon of Ra is first attempted to be used by Odion only to be rejected as Odion wasn’t considered worthy enough to summon it. The Winged Dragon of Ra has multiple effects: it receives the combined ATK and DEF of the 3 monsters required to be tribute to summon it (just like the other 2 God cards), can receive a point to point transfer from life points to ATK and DEF of the duelist’s choosing, and attack multiple monsters at once. Needless to say, it’s arguably the best God card. Yami Marik uses it very effectively against Yami Bakura in their grudge match as well as against Joey in the semifinals and Yugi in the finals of the Battle City Tournament. Truly a card that defines what it means to be “OP”.

He may have only been summoned once, but Exodia is by far the most powerful monster in the series. With an effect of automatically winning the game if all 5 cards needed to piece him together are drawn, Exodia skips the fighting and moves straight towards the winning. Yami Yugi was able to draw all 5 pieces against his first ever duel with Kaiba to begin the series, and not a moment too soon; nothing else Yugi had could defeat 3 Blue Eyes White dragons. It’s unfortunate that Weevil Underwood threw all 5 pieces into the ocean, and even though Joey saved a couple pieces, Exodia was finished. However, there’s no denying that automatic win condition, and Exodia can obliterate anything it goes up against in this card game.