While many of us hold Pokémon near and dear to our hearts, it wasn't the only battle monster anime from our childhood. Originally a manga first published in 1996, Yu-Gi-Oh! went on to spawn an abridged anime series, several spin-off series and films, many video games, and a real-life trading card game. It holds a relatively darker premise than most other shonens (demographic of teenage males) of the time, partly evident by the fact that the monster battles themselves were known as Shadow Games (one of which is the Duel Monsters we know so well).
As such, the series has a plethora of dark themes and creepy implications. From the manga to the cards themselves, the lore is vast and almost impossible to keep up with. This isn't even counting the various changes that had to be made when the series was dubbed to the English version. In Japan the target audience was adults, young and old. But in America, producers wanted to censor the show for children. As such, many scenes you do remember might've gone down much more horrifically in the Japanese originals.
In real life, if you lose a game of Yu-Gi-Oh!, the only thing that gets hurt is your dignity. But in the manga and anime, losing (or cheating in) a Shadow Game leads to a punishment called a Penalty Game. They were fairly prominent early on in the series, but the bloody murders were toned down a bit as the story went on and Yugi stopped employing them. Most of them were based specifically on the crime of the victim.
One such penalty game is called The Experience of Death, essentially a super dark version of what Hell might be like. The victim suffers illusions of being killed by monsters over and over again. It's one of the more horrifying Penalty Games, only ever used by Yugi on Seto Kaiba.
This may not come as a surprise to most people, but the series' main protagonist is certifiably insane in the manga, and even more so in the anime. I could pull up a myriad of examples, but one of the most unsettling comes from his work on Death-T. This is essentially a virtual reality version of Shadow Games, rigged in his favor and made up of some of the most disturbing challenges a human mind can come up with. Also, the players are very much capable of dying, as well as losing a limb or getting electrocuted.
Death-T has five levels, each of which is more difficult than the last, ending a final showdown of Duel Monsters between Dark Yugi and Seto Kaiba. Spoiler alert, Yugi wins with Exodia.
Perhaps the most disturbing aspect of Death-T is that Kaiba designed it all himself, not from his memory of any Penalty Game. It was his own original idea.
While a more commonplace concept for those of us who are older, death is a much darker mystery to younger audiences, and often portrayed differently in shows with such a demographic. In the Ocean Dub of Dragon Ball Z, people who died simply when to "Another Dimension."
In Yu-Gi-Oh!, the dead were sent to the Shadow Realm which is essentially Hell, but euphemistically used to avoid saying the words like "death" or "killed." Somehow, the creators thought that a plane of eternal torment and horror would be better than just dying. It does however, allow for the possibility for those who were "banished" to return to the real world, should the plot call for such an event.
In Yu-Gi-Oh!, you've got happy cards like Dark Magician Girl and Kuriboh (kinda), which are showcased most often. But other specialty decks contain cards far more horrifying, both artistically and conceptually. One of the most chilling examples is the Gimmick Puppets archetype. On such card is the Gimmick Puppet Dreary Doll, which was originally a doll made from the likeness of a child, covered in bloody bandages and sitting in a coffin (toned down for later releases). Another is Gimmick Puppet Shadow Feeler, which shows two puppets on all fours and facing each other, with their heads fused together into another half-torso with arms.
It's unclear what dark corner of the human mind these cards came from, but needless to say, most were redesigned for releases beyond Japan.
On the subject of creepy cards, another that makes the list is Parasite Paracide, an insect card with unnerving art and skin-crawling (literally) effect. It's used by the infamous Weevil Underwood in the manga and anime. Originally, the card art showed a giant insect literally crawling in and out of a person's face. The Japanese anime even had a scene where Weevil used the card on Joey Wheeler, who then had insect limbs coming out of his body.
Of course, a lot of this was removed and changed for the American release. The card art showed just the parasite itself (creepy enough) and the scene itself was removed from the English dub.
In the iconic movie spin-off, Yu-Gi-Oh! The Movie: Pyramid of Light, we get a glimpse of what it's actually like inside the millennium puzzle. Yugi Muto is trapped within while Yami Yugi battles Kaiba in a game of Duel Monsters. In a particular scene, he runs through the mind-bending labyrinth from door to door, each yielding nothing but more than another maze behind it.
Yugi goes nearly insane after a few minutes inside this dimensional prison. So one can only imagine how the Pharaoh must've endured 5000 years of it. At least he wasn't alone, the soul of Anubis, his mortal enemy, was trapped within the Puzzle as well.
Marik's Millennium Item also has the ability to turn any duel into a Shadow Duel, which causes players to suffer the same pain as their monsters during the game. This is especially terrible when you realize that his entire deck is based on torture, and he enjoys inflicting punishment on his enemies.
His duel with Mai Valentine was turned into a Shadow Duel, causing her to suffer an inhuman amount of anguish. Some might remember the scenes in the dub where she simply loses her memories. But the source material was far more graphic. At the end of the duel, upon losing, her mind is trapped in an hourglass; when the sand runs out, she dies.
Not many fans of the original manga and anime made it far enough to watch the quirky spin-off Yu-Gi-Oh! GX. Sure, it was technically for children, but some of the plot lines were so crazy that even young minds might have difficulty comprehending it.
One example is a two-part episode called Duel Distractions, which highlights just how deeply rooting the practice of dueling is in that society. The episode's villain is an Amazonian woman called Tania, who demands that one of the students of Duel Academy must duel her. If she wins, the loser must marry her. This would sound silly, but in the Yu-Gi-Oh universe, refusing a duel challenge is impossible and Duel Monsters is law.
Bastion, the guy who ends up dueling Tania, actually falls in love with her during the duel and ends up losing. They consummate the marriage in the arena, obviously, but Tania says Bastion isn't enough to be her husband. Then she turns into a Tiger. It's all canon.
Some of think back less than fondly on the first season of the anime, when Yugi summons a Dark Magician out of nowhere, and all of us collectively yelled "YOU NEED TWO TRIBUTES FOR THAT, YOU CHEATER!" While the rulebook in real life has remained mostly unchanged, the duels in the show don't often follow the same guidelines.
Some might say it's for the sake of plot convenience; planning out the hundreds of games in the series according to meticulous rules might be a daunting task. Plus, it makes it easier to pull out a last-second, dramatic, unexpected draw for the win. However, the real reason is more capitalistic. The creators hope kids will buy more cards if they see how "powerful" they can be, with little regard to whether or not they'll actually learn the rules.
It's a miracle that a 5000-year-old Pharaoh is so well-adjusted in modern society. He acts as a father figure to Yugi Muto (whose own dad doesn't appear at all during the series) and is the voice of reason and justice. He's very different from other spirits such as Yami Marik, who use their powers for great evil.
The prevailing theory is that the soul of Yugi Muto is balancing force that keeps Yami Yugi in check. In the show, you'll see on several occasions when the Pharaoh is about to issue an especially heinous Penalty Game or do something else dubious, he is only stopped by Yugi's moral reasoning. The duo has always been seen as the good guys, but it makes you wonder whether the Pharaoh would still be on the side of justice if he didn't have someone to set him straight. After all, the other various "Yami" counterparts in the show are all evil. And the word "Yami" itself means dark.
If you're a believer of ghosts and the like, then you'll be intrigued to know that Duel Monsters has a real-life counterpart in the form of the popular spirit board, not in practice but in origin story. Back in the age of empires, a Chinese emperor actually outlawed ouija boards because he believed they were generally dangerous objects. Then, in more recent years, the board was popularized through mass production and commercialization.
Similarly, Duel Monsters is a deadly Shadow Game that was banned in Egypt long ago. However, the game was revived by Maximillion Pegasus, who capitalized on it at the cost of civilization's safety. I suppose the only difference is, besides a couple movies, that ouija boards haven't taken over modern society.
It's normal for the protagonist of a shonen to win literally every single time, until some finale where the bad guy is overpowered for once (but the protagonist wins anyway). In Yu-Gi-Oh, this victory is attributed to the famous "heart of the cards"; the belief is that a duelist need only believe in their deck, and they'll draw their way to victory (play one game of Hearthstone and you'll be convinced that it's not a real thing).
However, it's strange to think that Yugi is the only person in the entire world that actually believes in his deck, or at least believes in it more than his opponents. The more likely explanation lies in the power of the Millennium Items. Each one has a certain power, and it's believed that Yugi's puzzle isn't just flashy neckwear holding the soul of the Pharaoh; it's actually an insanely effective good luck charm. Perhaps he's not such a skilled duelist after all, it's just good luck (how else could he draw all five pieces of Exodia so many times?)
Yu-Gi-Oh! GX officially takes place ten years after the events of the original anime, after Kaiba sets up the Duel Academy, a school for young duelists. The main character, Jaden, is known for battling with an Elemental Hero deck and his Winged Kuriboh, given to him by Yugi Muto near the beginning of the series.
However, in the series finale, Jaden goes back in time to duel Yugi and uses the Winged Kuriboh. This suggests that Yugi gave him the card because he had already met Jaden, and knew he would use it in their final duel. Thus, the entire show is in a time loop.
While the series is known best for its trading card game, the premise actually includes a collection of games that fall under the Shadow Game category. Each has the same outcome of the loser suffering from a Penalty Game, with the added effect of the player's souls and bodies becoming part of the match.
These were first used in ancient Egypt, established using powerful sorcery, and then repurposed in the modern day. Yugi's title as the King of Games actually comes from his mastery of all Shadow Games, not just Duel Monsters. This is partly the reason so many spin-offs seemed to feature different mechanics of summoning. Challenging someone to a Shadow Game can only be done through possession of a Millennium Item.
As a child, Jaden's favorite card was Yubel, a fairly overpowered card in terms of effects, and even more so in practice. Every time Jaden used the card, his opponents would suffer seizures and fall into comas. Why Jaden allowed it to happen more than once is another question entirely.
Anyway, skip forward about a hundred episodes, when the students of Duel Academy are met with 'duel ghouls' that are forced to duel over and over until they exhaust themselves and also turn into ghouls. The antagonist responsible for this is revealed to be Yubel in the flesh. The first creepy thing is the fact that he/she doesn't have a fixed gender, but swaps between a male and female voice. Also, he/she looks like the result of Yami Marik and Yami Bakura (both antagonists) having a child. And lastly, Yubel seems to have a kind of crush on Jaden, and everything he/she does is a representation of his/her love.
Going through every disturbing baddie of the series would take a pretty long list, but some stand above the rest in terms of creep factor. One such enemy in the anime was a kid called Haiyama. Originally, it was believed he was being bullied by someone called Kujirada. Later, the opposite is revealed, with the creepy kid dealing the pain (with a whip). We learn that he has a history of such behavior, even mistreating his own digital pets (essentially the Tamagotchi of the Yu-Gi-Oh! universe).
Naturally, Yugi defeats Haiyama in a duel, and his Penalty Game is an illusion of him being eaten alive by his digital pet. Oddly enough, it was one of the few times the anime was even darker than the manga.
Something that's a little sugar-coated in the American release is the concept of possession. We know Yugi's possession is consensual, but Marik Ishtar, or rather, his alter ego Yami Marik, doesn't follow the same rules. He's the primary antagonist of season two, and he has the ability of mind control through possession.
Both personalities were enemies of the Pharaoh Yugi, and Marik killed Ishtar's father, a loyalist to the Pharaoh, when he was younger. Later on, Marik uses mind control on Yugi's friends to coerce him into playing a Shadow Game. It might seem generically devious at first, but the concept of mind control itself, at such a powerful level, is something the show often explores, at least in the Japanese version.
On the subject of mind control, another unsettling example comes from the Yu-Gi-Oh! Arc-V spin-off. There is a card called Parasite Fusioner that has some horrifying concept art but a fairly levelled effect. However, a character called the Doktor has created real-life versions of them, and is able to remotely control the brains of several other characters by implanting the parasites in their brains. Beyond just mind control, he has power over their speech and even facial expressions.
To add to the terrifying concept, when the Doktor's control over the character Rin is finally severed by the protagonist Yugo, the parasite itself takes control. Rather than speak as the Doktor, Rin speaks in creepy monotone.
And on the subject of face parasites, a certain Dark Yu-Gi-Oh card perfectly embodies the image, and surprisingly wasn't ever censored. With a fitting name, Necroface features the puppet-like head of a baby with the area around the left eye socket broken open by a creature attempting to crawl out. Tendrils are bursting out all over the head, which looks to be cracking as if it's made of ceramic. What's worse, the single eye that still is intact seems to be silently crying out for help.
The effect returns banished cards to the deck, and grants the monster attack points proportional the number of cards returned. The card is never used in the anime (because that would be too horrific, right?) but does appear in a couple of the video games.
Egyptian mythology is primarily polytheistic, with a belief in many gods that all rule their own part of the universe. This is reflected in the three Egyptian God Cards: Obelisk, Slifer, and the Winged Dragon of Ra. However, there is a monster more powerful than all three, and we all know him as Exodia, The Forbidden One. He's so powerful that he is split into five cards, and holding them all in your hand at any time automatically wins you the duel.
This leads many to believe that Exodia is the Judeo-Christian God Himself. It doesn't make sense considering Egyptian religion, but his power, coupled with the fact that his name is based on Jewish history, lends credence to the theory.