How does the universe work? Is it infinite? If it's not, then why does it seem to never end?

Those are the questions asked by beings that live in lower dimensions, questions that took us Guardian billions of years to find the answers, which turned out to be very intriguing: we live in a multiverse, an infinite quantity of finite universes all coexisting in harmony. Such an answer allowed us to find others, such as the truth about the apparent infinity of every universe: at the frontier of a universe, everything starts to get fussy, which allows the formation of sinkholes, a type of wormhole that acts like a bridge between universes, therefore uniting both for a few seconds at a time.

All of these answers brought other questions, such as How can we reach other universes? and How are they like? these to specific question led the a species of aliens to evolve in to a technological Utopia: they learned how to break the laws of physics, how to surpass the speed of light and, eventually, how to leave our universe.

Such an accomplishment led them to understand a few things: every universe was different, in ways most won't believe: the laws of physics change in every universe, every timeline is different and, most importantly, humans, a very curious species: weak, stupid but at the same time strong and brilliant, sons of war and chaos but lovers of peace and harmony, a specie worth protecting in universes worth protecting.

A decision like that brought the need for mapping the multiverse, which was easier than it was originally thought, you see every universe orbits around one main universe in a circular fashion, with a fix amount of universes per rim, with the closest rim to the main universe having 4 universes, and every rim after that having three times as much universes than the previous. Such a discovery baffled us, why would it happen? It turns out the main the universe protects the rest, emitting an energy shield around the other universes, who, in turn provide the energy to generate such a shield. Which brought a problem, it locked the universes in to a fix set of events that if altered would lead to the universe collapsing on itself.

In order to keep protecting the multiverse and humanity, they couldn't interfere directly, luckily, because of their fifth dimensional properties they could change their physical appearance and blend in. And so they became the silent Guardians of the Multiverse.