The "Dimensional Merge" theory is a most obscure, insane, and widely unacceptable theory that I first heard from a certain insane man, now woman, called Chris Chan.
Perhaps some of you already have some familiarity with this person, and perhaps some of you do not. Chris Chan is an American transgender woman with low-functioning autism who also appears to be suffering from a declining, or should I say, rising, mental illness. They're in prison currently for a crime so shameful I'd best not mention it in this article.
With their declining sanity, Chan have seemed to have eventually lost the ability to not only tell truth from lie, but also reality from fiction. As a result, they are easily manipulated, as they were in the past by online trolls, and they see themselves as married to the characters they created in their minds and comics.
The "Dimensional Merge" is a multiverse-esque theory that recognizes all fiction as truth; that characters such as Bugs Bunny and so on actually live in their own, separate universes and are as real as we are. It says that eventually, these "dimensions" will begin to collide with one another, thus creating a bigger universe from the merged dimensions.
To regard any credibiliy to this theory we must assume credibility to the multiverse theory, by the way.
If such a thing is to ever "happen", then things and characters we once recognized as fiction "will be" as real and interactable as any other thing or being.
If you are familiar with Chan (not to be confused with another person I mentioned on this site), then you might already know that almost no one takes them seriously. Their grip on reality is questionable, and so is their understanding of it.
It's like they're living in a whole different world; a whole more, childish, and, at the same time, disturbing world. I know this is technically an ad hominem fallacy, which says that concentrating on the person is irrelevant to the idea, but I'm sure there are exceptions, because sometimes, the idea and the person are so intertwined that both need to be addressed significantly enough to understand the idea at hand.
Perhaps this is why the ad-hominem fallacy came about in the first place; to allow certain voices, such as mine, to be heard and not thrown out the window just because I don't have the mental energies to get a degree in philosophy (although I tried and read a lot back then).
I believe that this universe wouldn't be able to stand so many universes, colliding into it. I'm saying this not from a scientific standpoint, but from the idea that so many characters, with different powers and abilities, far greater than ours, breach this "dimension" and become living beings.
Many, many of these fictional beings, such as Galactus from Marvel (wrote an article about him before), would terrorize whole planets and populations; If Sauron is unleashed on Earth, he'll be strong enough to become the next Hitler. If characters from the "Mortal Kombat" universe exist "for real", then they would be butchering us left and right.
Although the dimensional shift might never happen at all, and although fiction is pretty much an illusion that we consume as a product, this theory does teach us the horror of fiction. I'm not referring only to video games. Imagine if the gods from Greek mythology actually existed, then we'd be in a constant state of turmoil; if golems existed, from Jewish mythology, then someone capable enough could've created a constantly generated army of them and unleashed them upon the world. And so on and so forth.
Even pieces of fiction for children could be quite horrific if existed in the real world and not in our imaginations. A plumber that is able to smash beings by jumping on them; a hedgehog that is essentially a living, spinning-saw, capable of.. well, doing things a saw can.
Magic, essentially, could be a great source of horror if applied in certain ways, like pyromancy, or fire magic, or cyromancy, -- ice magic, all within one's hands without necessarily needing any tools beyond knowledge of the fictitious arcane.
Out of all the darker philosophical concepts I have written about, the Dimensional Merge's influence on the universe is a great understatement, if it ever had any likelihood whatsoever. Fiction is a label that, in a way, says to us: "You are safe, for you are in reality, and the things and beings in fiction can't actually hurt you".
This is why horror as a genre isn't as scary to certain people as it is to others; whatever source of horror is out there, on the screen, in a book, and so on, it can't hurt you physically, just like people on the internet who can't come to you physically and do so themselves.
Just be thankful that fiction is fiction and reality is reality, even if you let your child play violent video games or let your teenager watch a scary movie. It might hurt their minds, or at least disturb them, but they will never have any agency beyond the mental one; the ones that "exist" in their mental life and in their entertainment.
Also, if you have a gentle heart, please don't look at what Chris Chan did that got him/her to prison. I don't really like trigger warnings, but such things are not good even for some adults. I found it absurd when I've heard of it myself.