Far away into the multiverse, several events were taking place. Under normal circumstances they would have gone on completely unnoticed by each other however due to the intervention by an unknown entity, they all happened all at once.

All Marvel universes

The Beyonders have just finished destroying the Marvel multiverse, before retreating to their home dimension. Had there been anybody left to see, them they would have noticed that Beyonders were smiling.

Finally their purpose had been fulfilled, as the tear between dimensions closed a burst of pure energy shoots out of it initiating the birth of a new universe, and with it a new multiverse.

All

Darkside had won the Earth along with the Anti Life equation were under his control. Whatever heroes were left had gathers to stop him, Superman had used the sun's rays gathered within him to power the Miracle machine.

Seeing that this wasn't enough Captain Marvel used all of his magick, along with him Lex Luthor gave up his great intellect to try and stabilise it. This caused a chain reaction, killing Darkside and initiating the birth of a new universe.

Warhammer 40k

The Emperor had died but in an attempt to stop the Eye of Terror from consuming all of existence he did the unthinkable.

He called out to his children and Humanity had answered, turning himself into a concentration of Order he struck the Eldar Chaos god of Death setting it free in a united strike the attack the other four.

Their war was so great that both the material realm, and the warp merged effectively destroying them both. However that was the plan the new universe would have equal levels of chaos and order.

These events and others like them occurred all over the Multiverse, had that beeing not interfered they would have stayed isolated. However that would have been no fun, so using the combined energy he assaulted all dimensions.

Anime, Manga, Comics, Cartoons, Movies, video games, table Games, Books, nothing would be spared.

However making things from scratch would be too difficult, to in the creation but in the person per say, so he would do the unthinkable.

The universes already had their people, so he simply transferred them. The only question was where and the answer was simple the first univers.

But how would it be a boom, a rack or simply by apparition? No it would start by a simple set of words.

''Get your hot dogs here! a street vendor yells attempting to gather customers, as it's already noon and he has failed to sell one thing. All of a sudden an Earthquake occurs, not much to talk about, as it simply comes and goes never to be felt again.

It's amazing what Humans can miss, as in one moment the planet Earth was the cize of Jupiter, in fact all of the planets in the solar system, along with their moons were larger.

Suddenly the Internet ether became incredibly advanced or regressed to earlier stages, for an instant that felt like an eternity the world stopped.

All across the planet events that baffled Humanity began to occur, a massive pyramid made of gold appeared near Africa.

Japan became the sight of a massive war, as the ages past collided with the feature, along with the present.

Mexico's streets ran with milk and honey but what struck people were the massive flying cities in the sky.

Then it happened