Integrated Dimension Theory

WARNING! This article may contain spoilers from various Yu-Gi-Oh! Series. You have been warned. Integrated Dimension Theory is set to be the canon theory for the explanation of each dimension's existence, in Yu-Gi-Oh! HYPERFORCE!

Explanation of the Theory
The Integrated Dimension Theory states that every separate dimension within the Yu-Gi-Oh! Universe is, in fact, the exact same universe, albeit they are at different points in time. Although there is definite differences in each dimension, this theory explains that, when Zarc split the dimensions into all the new kinds of dimensions, he did not create new universes, rather made different variations of them.

Issues with the Thoery (+ explanations)
Q: Wouldn't the protagonists exist in each dimension? A: Yes, and they do. The reason the other series' protagonists do not appear in the series is because they are no longer in the relevant areas (Yami went back to Egypt, Judai left for his own adventures, Yusei did leave Neo Domino, as seen in Tag Force! Special, Yuma & the gang, besides Kaito, had been carded by Academia, and Yuya would have been travelling with the other Lancers). Q: How would Constellation Summon fit into everything? A: This series takes place after the dimensions had previously become one, and also after the ending of VRAINS. Q: If that's the case, how would they know about the threats prior to the reforming of the dimensions? A: As seen from the last few episodes of ARC-V, the people of Miami City was able to remember the events of Zarc, so it's natural they'd be able to remember things prior to the reforming of the dimensions. Q: If this is true, wouldn't the universe's Big Bang occur again after Zarc is reborn, and the dimensions become one? A: Yes, and it nearly did. However, Reira was able to stop the splitting, and so only the same amount of universes were reborn, and because of the previously explained differences, they were able to reform as 1 after the successful, normal Crunch (explained next). (Feel free to ask about any other issues).

Supporting Real Life Evidence
The Big Crunch Theory: This theory explains how the universe will end, and that the only thing that can exist afterward is the matter at the epicenter of the crunch, which is the energy for the next Big Bang. It's unlikely, but not impossible, for Ray, Zarc, and Leo to be at the epicenter of the Crunch (with Zarc in the direct epicenter, as he was likely the one whom split the universe into however many dimensions there is). This would also explain how Zarc is able to possess the Yu's, regardless of which dimension they are in, as well as have his influence over each dimension, AND why Leo and Ray were able to be revived afterward. This theory also states that the universe that is recreated from the Big Bang will be the same as the previous one, with some scale differences (which supports parallel universes also), however time will start from its original point; at the same time as the previous universe's beginning. Darkness: Darkness was able to predict the future, all the way up the events of ARC-V, which he told Judai about during their duel. He had shown no sense of precognition previously, and if he had, he would have known about God Neos in the final part of their duel. As a result, it can only mean that these events have happened before (the original dimension). Dimensional Differences: Each dimension is more futuristic than the other (e.g. Standard, which according to this theory occurs last, is the most advanced dimension, as the other dimensions received most of their technological knowledge from Standard). It also explains why each dimension only has their normal summon method, as the older ones were too primitive, but why older monsters also exist in Heartland, but the past dimensions were able to quickly advance their cards because of Standard's technology.