Saying that the Yu-Gi-Oh! anime took liberties with the card game doesn't even begin on the half of it. There are actually many cards that didn't even exist that were added to the show.
Remember Valon's armor cards? Literally he and Joey were just punching each other the entire duel, nonsense. However, some of these cards (not Valon's) have since been made into real cards that are present in the TCG. Today, we'll be going over ten of those. Let's get into it.
The Seal of Orichalcos
The Seal of Orichalcos (and the absolute mess of cards that went with it) wasn't printed until years after its release. Of course, it had to be heavily nerfed when released, and only retained its soul-stealing powers in the real world.
Most of Dartz's deck never made it out alive, but this card did, with all of its effects essentially being nerfed versions of its anime effects. No back row of monsters, that was absolute nonsense. Just like this entire season.
The Legendary Dragons
The Legendary Dragons were probably never meant to be printed, as they're cards that can merge with any creature in the anime. These plot-armor... um, gifts, are given to Kaiba, Yugi, and Joey in order to take down Dartz.
Yeah, lots of season four and five in this list because they really gave up on cards that actually existed at this point. Either way, these three eventually made it to the TCG in the form of spell cards that can merge into some of the forms that we did see in the anime.
Kuribandit
Season four introduced eighteen different Kuribohs and a weird mechanic where they all ate each other for no reason at all, and Kuribandit ended up being the one that we actually got in the TCG when all was said and done.
This guy allows you to excavate some cards from the top of your deck, and was used prominently by Yugi when he wasn't too busy sacrificing Dark Magician Girl's soul in his free time. Give us the Kuriboh Brothers next it's what we deserve. We've earned that one.
The Golden Castle Of Stromberg
This card was an illegal card that was played by Leon in his duel against Yugi. Zigfried had the ability to hack the card and make it far more powerful than it ever should have been, and Yugi only actually managed to destroy it due to a technicality in the card's rulings.
Naturally, they ignored the Kuriboh Brothers for the stupid omniscient castle, and printed this card. The castle has several abilities that make it hard to compete against, even if it (obviously) isn't as strong as its anime counterpart. It has some great synergy with some cards that we'll be getting to later in the list.
The Valkyries
Zigfried's Valkyries were another set of cards that took years to get their own printing. All of these cards have great synergy, and pair up great with all of the other new Zigfried cards, including the goddess cards.
While weak on their own, when all of these are played in tandem correctly, your opponent can have a tough time taking them down. Kaiba almost got bested by these cards, while Weevil and Rex were taken down in a single turn by these horse girls.
Hexe Trude
Hexe Trude was another one of Leon's cards that we saw in his duel against Yugi. This card is one of many that specifically lists the Golden Castle in its description, as it can be summoned straight to the field without tributes when that card is on the field.
Otherwise, it can attack more than once per turn and is a 2600 ATK beatstick, so it's a fun card to mess around with. Too bad it got BODIED by Dark Magician in the anime. Literally wrecked.
Prinzessin
Originally called Cinderalla, but because of Disney we got Prinzessin. This is another one of Leon's fairy tale cards that pairs with the Golden Castle of Stromberg. Besides that, the card has several different support cards that can make it quite a challenge for opponents to deal with.
With her glass slippers and pumpkin carriage to help her out, she's infuriatingly dramatic. Like, this girl threw seven pairs of shoes at Yugi during their duel. Can you please calm down?
The Goddesses
The Goddess cards were Zigfried's second archetype that he used in conjunction with the Valkyries. These monsters could be used to systematically dismantle your opponent's deck when they're all out on the field at the same time.
They're meant to be used with the Valkyries, so combining them with those cards can make them even more devastating than they already are. Isn't it fun when anime creators just decide that cards exist? So much magic can happen.
Harpie Lady Phoenix Formation
Harpie Lady Phoenix Formation was a card that was used by Mai Valentine when she was under the influence of the Seal of Orichalcos. While the card's counterpart, Sparrow Formation, never managed to make it out of the anime, this card managed to get a printing a few years after airing.
The card allows you to destroy your opponent's monsters up to the number of Harpies you control, and then inflict damage to them. Though, the fact that you can't conduct your battle phase or special summon the turn this card was activated makes it somewhat of a weak choice compared to others on this list.
The God Cards
While these cards were probably always meant to get a printing, they sure took their sweet time getting there. They originally got an illegal printing with flavor text before they got their official variants. These cards are famously, to put it bluntly, trash. They really can't do much of anything when it comes down to it, with Obelisk being the best of the bunch, ironically.
You shouldn't really ever play these cards in any competitive capacity, and rather appreciate them for all of the power that we all pretend that they hold.