The entirety of the original Yu-Gi-Oh! series has its fair share of mystical and technological elements. Contrasting the supernatural aspect of the card game, Seto Kaiba and the rest of KaibaCorp is centered around dueling technology. And it's this technology that the Virtual World arc explores in more depth, which includes a strange A.I. battle for KaibaCorp itself.
During the Battle City arc, which is considered to be one of the most memorable aspects of Yu-Gi-Oh!, the stages of dueling between competitors are interrupted by a “ghost” from Kaiba’s past. While traveling on an airship to their destination, the duelists on-board are rerouted, and it's revealed that the "Big Five" are behind their entrapment.
The Big Five is a group of businessmen who helped to run KaibaCorp under the Kaiba family. While they had darker plans for the company, Seto and others ended up getting in the way of their schemes. They intended to take over KaibaCorp but the defeat of Pegasus in Duelist Kingdom and the loss of the Big Five’s Five-Headed Dragon delayed their plans.
As an act of revenge, Yugi Moto and Seto Kaiba are taken into a virtual world along with their friends. In this world, the Big Five only has one objective: to defeat everyone in a good old duel. Losing to any of these businessmen means losing your own body, something which Tristan ends up falling victim to. Weirdly, his soul ends up in a robotic monkey body, although he still continues to tag along with the group.
The Virtual World arc brought to the table a summoning mechanic which, like Capsule Monsters, has never be adapted into a real one outside of the anime. All of the duelists in this world have access to a Deck Master, a monster that accompanies them and can be summoned to the field regardless of level. While Deck Masters have their own attack stats to fall back on, they also possess abilities that go beyond the original card text. An example of this is Yugi’s Kuriboh, who can negate damage dealt by an opponent’s monster once during either player’s turn.
Each duel against these five businessmen has its own wild element, but none of the Big Five has any particular prowess when it comes to dueling. While Tristan sacrifices himself in a three-on-one match against Nezbit, everybody else manages to defeat the members of the Big Five in their respective duels. Even Tea, who is rarely shown dueling in the show, defeats the businessman who wanted to take over her body.
In that sense, all of these villains are just a warm-up for what comes afterward. This arc reveals that Kaiba’s past is more complicated than it may seem on the surface. Gozaburo Kaiba had a son before he adopted Seto and Mokuba into the Kaiba family. This son was named Noah, and during his childhood, Noah was set to become the next heir to KaibaCorp. His dreams of inheriting the company were stopped when Noah was hit in an accident, causing his body to be destroyed while his mind was preserved in Gozaburo’s Virtual World.
Noah watches over the duels of the Big Five from a safe place while setting some smaller pieces into motion. Noah's real goal is to use the Big Five to take Mokuba from Kaiba’s group so he can coax him into thinking that Noah is his real brother. In doing so, he wanted to show that he was truly worthy of running KaibaCorp instead of Seto. When the Big Five loses their individual duels they all converge into Tristan’s body and use it to face off against Yugi and Joey, putting all of their bodies on the line while Kaiba chases after Mokuba.
After the Big Five lose their important match, Noah enters the fray and duels Seto Kaiba himself. While the turns go on, Kaiba gets a chance to finish off Noah once and for all. However, Noah retaliates by using Mokuba as a human shield. Noah effectively brainwashes Mokuba, meaning that the poor kid doesn't have any knowledge of the fact he is in harm's way. This cruel gambit pays off though as Seto refuses to perform any action that will hurt his little brother. The bond between Seto and Mokuba eventually breaks through this brainwashing, but due to Seto’s inaction Noah takes the opportunity to finish him off.
This triggers Yugi, and while the Kaiba brothers are turned into stone he picks up the duel that Kaiba couldn’t complete. Yugi’s duel against Noah features one of his luckiest drawing moments in the duration of the King of Games' seasons. Thanks to Card Of Sanctity, Yugi draws the exact cards that he needs to take down Noah’s 10,000 life points. The situation is something that would be near statistically impossible in the card game, but Yugi’s “heart of the cards” helps him get the win.
While they defeat Noah, this arc becomes more complicated because of Gozaburo Kaiba's appearance near the end. Although he disappeared from Kaiba’s life after losing the majority of KaibaCorp’s shares, he uploaded his consciousness into the virtual world that Noah inhabits.
If this arc couldn't get any wilder, Kaiba ends up confronting his adoptive father in the virtual world and proceeds to have a duel with him. At this point in time, Gozaburo Kaiba has power over the virtual world that rivals Noah. Despite this mass of power, like most conflicts in Yu-Gi-Oh!, problems are resolved through a classic duel.
If there is one thing that the Virtual World arc has to offer, it's to develop Kaiba's character as something beyond his unending rivalry with Yami Yugi. Trying to rescue Mokuba shows how, despite the fact that he is busy running his company, he still has makes his family a priority when he needs to. On top of that, his duel against Gozaburo allows Kaiba to confront the man that he took down to take control of KaibaCorp.
This duel features a lot of elements that bring audiences back to early episodes of the show. Firstly, Gozaburo and Seto duel in a virtual field that looks like the place where Seto lost to Yugi's Exodia. Secondly, Gozaburo himself uses a form of Exodia called "Exodia Necross." Using the monster requires sending the pieces of Exodia to the grave rather than collecting them in-hand; a fitting contrast to Yugi's use of the cards considering that Gozaburo is technically in the "grave" with Noah.
Despite confronting these demons, Kaiba defeats Gozaburo in their duel and proceeds to escape the virtual world with Yugi's group. The aftermath of this fight only emphasizes Gozaburo's power since, in an explosion that their aircraft escapes from, his face could be seen rising out of the flames. However, Noah and Gozaburo do end up passing away -- never to be seen again.
