Ultraverse is a looped dimensional kind of spacetime, which serves as quick gateway to different sizes. Ultraverse diagonalizes most Archverses in a Infinityverse. Each Ultraverse has 3 spatial dimensions that are looped by a Infinityverse.
Ultraverse seems to be safe for dangerous scenarios, as only creatures can go through gray holes by a special kind, such as humans and other civilizations.
However, no Ultraverses could be found in Infinityverses that diagonalize all powers with -layered sets or higher.
They can be defined as Archverses that are infinite sets of smaller Archverses, and can be assigned to numbers in sets by layers, depending on Infinityverses.
Under 0.01% of a Ultraverse consists with most Archverses in a Infinityverse. Archverses in a Ultraverse appear to be spheres, with identical physical properties. Ultraverses can have different properties just like their lower counterparts, since they are contained by a higher Infinityverse.
Creating a gray hole from any Archverse always leads to the creation of its counterpart in a Ultraverse, if the axis is parallel to a looped / nonexistent dimension. Therefore, at the creation of a Infinityverse, a Ultraverse would be basically a purple void inside a Infinityverse.
Our Ultraverse contains all Archverses in our Omniverse, that are at least Megaversal-level. Only teraversal civilizations and higher can safely enter Ultraverse, as those civilizations can use Macroformers, which can be mostly found in some Extraverses and archverses higher than a Teraverse. Macroformers can be also used to pull Archverses to their homeplace in our Ultraverse.
The size of our Ultraverse is same as our Omniverse, but one dimension has 10x lesser size than our Omniverse instead.