I said it's cooked because there's so many interpretations and none of them have really been confirmed or denied. Many things are equally as true as each other.
Anyway, fine, I'll lay it all out for you guys.
What we know so far (100% certainty):
- Hyperspace is at the very least 4-Dimensional (Definition is "space of more than 3-dimensions." Blast refers to it as a higher plane that ignores distance, energy, and size, accompanied by a picture of a Tesseract. It is mentioned to be a higher-dimension multiple times. It contains infinite parallel universes folded like bubbles inside of it, which are likely to be 4th-dimension constructs based on the inference of Hyperspace being "outside the causality of the universe," meaning it is outside of temporality as well.
- Empty Void can enter Hyperspace. In this dimension, he appears larger than the individual bubble realities. Despite them being "folded like bubbles," due to the 4th-dimensional nature of the space, it is possible they are still retaining the size of an actual space-time. At the very least, this grants Void interdimensional travel and range.
- Dimensional Slash can be used to interfere with the bubble universes and attack areas inside of it from Hyperspace. It is explicitly stated by Blast to be an interference from the higher-dimension that ignores distance, energy, and size. It also explicitly cuts through space itself, as stated by Empty Void. As a result, it is guaranteed to be accepted as 4-Dimensional spatial manipulation, interdimensional range, and durability negation. Its physical range Varies based on what Void is targeting. It can be large enough to cleave apart tens of kilometers worth of space at the bare minimum. Though we also see galaxies visible in certain bubbles.
- Saitama catches Void's Dimensional Slashes with two fingers and pulls Void out of Hyperspace by dragging them down. Bare minimum, this means Saitama can resist a higher-dimensional space-cutting attack that negates durability. 4-D resistance to Spatial Manipulation and 4-D Non-Physical Interaction is practically guaranteed to be accepted.
Arguments Beyond the Certain:
- Hyperspace is 5th-Dimensional. This argument comes from the fact that Hyperspace could be higher-dimensional relative to not just 3-dimensions, but entire space-times, which are 4th-dimensional constructs. Reason being that it is said to be outside / beyond the causality of the universe. Causality is the process of cause and effect which is synonymous with temporality / time. It is furthermore given with the context of there being multiple parallel possibilities, which can only really exist throughout time. You could also make the argument that "Causality" refers to not only the timeline of single universe, but every single one of the branches themselves. Because of how its phrased with the imagery, this is actually a very strong argument. "Causality" is what causes the universe to branch out in the first place. So if Hyperspace is indeed beyond every single possibility, then it would be solidly 5th-dimensional. I would consider this argument to be STRONG. It could likely be convincing of a "Possibly" rating. This would furthermore scale to Dimensional Slash and Saitama.
- Empty Void is larger than Universes. This comes from the visualization of his technique, where he is shown to be larger than entire universes folded into bubbles. Even when they are showcased to encompass entire galaxies. If we take this visual completely literally, then Void would have Type 8 Large Size in this dimension. This would mean he has Immeasurable weight. This ends up scaling to Saitama, because he was able to pull an Immeasurably-sized entity out of higher-dimensional space. If accepted, it would give Saitama Immeasurable Lifting Strength. I consider this argument to be MEDIUM. 50/50 on whether or not it could even classify as a "possibly" rating on the pages. Its main strength comes from it being the most literal interpretation of the panels. Though, that is also its greatest weakness as more nuance and explanation can lead to it being quickly dismissed or countered. I could lean either way.
- Dimensional Slash is Infinite Speed. This argument is from the statement of Dimensional Slash ignoring distance and coming from a higher-dimension. Also the fact that it potentially just spawns into the universe when Void strikes the bubbles. I consider this argument to be WEAK. While the distance-ignoring statement is very good, it is hard-countered by it being shown to travel multiple times on panel, with multiple characters potentially even reacting to it on-panel. In particular, the showcase of it in Chapter 209 is damning, as it shows the blade travelling until it reaches Saitama. However, Blast and Void seem to think that Dimensional Slash can only be dodged by teleportation. Flashy also notes it isn't a technique that can be dodged with speed. At the very least, it completely BLITZES the hell out of Blast and Flashy Flash. Saitama will upscale significantly from whatever is accepted.
- Dimensional Slash is MASSIVELY FTL+. Argument comes from if you think the blade enters at the edge of the observable universe and then travels all the way down to Earth. Supporting evidence for this would be that the bubbles do include all of space-time within reality, given depictions of them holding entire galaxies. I consider this argument to be MEDIUM. You could just as easily say that it simply starts at the edge of where Void is focusing. Somewhere like above the clouds, as we see in Chapter 209. Saitama will upscale significantly from whatever is accepted.
- Saitama is Low 2-C. Argument comes from Saitama overpowering Empty Void, assuming that he is Low 2-C in size. I consider this argument to be WEAK. Even if we do assume Void is Low 2-C in size, this does not automatically grant Saitama Low 2-C AP since he didn't harm Void in that form, nor does Large Size inherently grant AP. We only see Void get "hurt" after he has been pulled back into the normal universe.
That's about all I can think of at the moment. There's probably more, but those are the main ones.
Note that the "strength" of arguments is just my personal opinion. Because we have no confirmation on many things, a lot of stuff could be more or less strong from other perspectives.
