The multiverse is a set of many unique Universes under a given continuous series of laws and is also the second in a series of Archverses. Uniqueness isn't mandatory, but is guaranteed due to the sensitivity of conditions during Universe formation.
Each Universe in a Multiverse, as stated above, shares in common laws of physics, systems of nature, sets of elementary particles and everything else that the laws of the parent Multiverse. However, since each Universe varies in initial conditions, the entire timeline is affected and entire cosmological structures are "reshuffled", so to speak.
We can use our own Universe as an example for ways other Universes vary in more than just timelines. For example, if the initial conditions are different enough, the ratio of matter to dark matter can be affected, the ratio between matter and anti-matter can change, and sometimes, it is possible that even constants can change by very tiny amounts, like the fine structure constantbeing very slightly different.
Multiverses average in size around 8 Quadrillion light-years, making our Multiverse slightly above average in diameter. Multiverses are also 4 dimensional, meaning that even though Universes are quite far away from eachother, despite not moving much, and there being copious amounts in each Multiverse, they still very rarely collide with one another and have a lot of space, whilst moving through 4 axis.
Similar to Universes, Multiverses have their own entire natural systems and structures, just like Universes. They are a byproduct of their Universes, so if a particularily strange and "mutated" Universe forms naturally within its Multiverse, it will have a strong impact on its surrounding ecosystem. However, most Multiverses have similar Universes, therefore they also appear to be homogenous.
Multiverse Formation
Upon the conception of the Proto-Xenoverse, instead of it being a perfect sphere, it becomes a tangled 6 dimensional mess. When mapped onto the 3rd dimension, the 3D surface crosses itself upon random points. In reality, these points are 4D Multiverses of deformed shape.
As the Proto-Xenoverse expands and pulls these folds back, they snap and decay, turning into Metaverses, as they degenerate into the lower 5th dimension, and their crossings become the 4th dimensional Multiverses. Every fold captures the crossings that it went through, which gives the Metaverses their own Multiverses right upon birth.
The chaotic nature of the Xenoverse generates sets of laws, like encrypted random quantum fluctuations, when processed properly, which is exactly what the folds and crossings do. However, there are many other ways to do it, other than the natural everyday process, which is how most artificial Metaverses and Multiverses used to be made (new technological advancements have made this process more and more antiquated).
Examples of Multiverses from other cosmologies/media/pop-culture
- Nexus of Reality
- Orrery of the Multiverse
- The Map of the DC Comics Multiverse
- Multiverse from DC Wikia
- Multiverse from Marvel Wikia
- Multiverse from Marvel Cinematic Universe Wikia
- Multi-Universe from Super Friends Wikia
- DC Multiverse from DC Universe Online Wikia
- DC Multiverse from Superheroes Wikia
- Multiverse from DC Universe Online Wikia
- Multiverse from TRwiki.net
- Multiverse from Transformers Wikia