You say it yourself, something physical can have powers such as non-physical interaction, conceptual manipulation, etc. This is exactly the case here, you are just looking for an excuse to ignore it.
Ignore it? How am I ignoring it, when I'm literally going to and exactly matching the definitions? I'll just quote this again
- Conversion to Nonexistence: The user of this ability might be capable of turning targets to nothing. This can range from only turning the matter of the target to nothing to also turning things like its energy, mind, soul, space, time and/or concept to nothing. Note that most users of this ability have not the full range of the ability. Further note that one shouldn't list a character to have resistance against this ability in total, as that requires a character to have shown resistance against every imaginable ability which can erase a target. - Source- Void Manipulation page
This is literally what Void and its negative energy does, and is clearly enough to be considered void manipulation.
At this point its you who's taking it out of context, when it has everything related to be classified as void manipulation, but you're taking it as anti-matter just for the sake of "it clashes with positive energy and turns it 0" when that falsifies absolutely nothing to it being void manipulation.
This is the way Fuse indexes Nihilistic Hazard, not the way the wiki indexes it. The wiki indexes abilities primarily by their feats in fiction, just read what Nihilistic Hazard does. An ability that literally destroys everything it interacts with, like a kind of anti-matter manipulation, and turns the world into void until it disappears. This is still a manipulation of nothingness, no one opposes it.
Once again, Anti-matter interacts with matter and the moment they so, it turns into an "Annihilation process" where energy is generated, not nonexistent energy even
In our case, it doesn't just interact with matter, it literally interacts with everything it comes into contact, even energy and concepts, turning them into 0. Refer to the highlighted line in the quote provided above, that's literally what void manipulation is
Anti-matter is dealt with in physics, its a physical process, when you remove that very property that it can only deal deal with physical stuff and instead can interact with concepts, and even at that, turn them into nothingness, there's nothing there left to identity it as "anti-matter", as it'd be void manipulation simply given the puppet name of "Anti-matter", the latter[it being called anti-matter] is not even the case here. Next thing I'd know is you saying nonexistent can't be proved irl so its not anti-matter, when in fact, this is fiction, not real life. Just because its "similar" to anti-matter irl[which is not even the case], doesn't mean its anti-matter manipulation. Trying to provide real-life counterarguments of it being anti-matter manipulation is false to begin with when nonexistence in its true sense is not provable in real life, literally said in the definition page itself
So again, your claims have literally 0 backing, while mine follow the definition pages word to word. If you really want to say something like that is not void manip but anti-matter, that's your problem with the definition page, and for that, its not me who you should debate, but a staff member