system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] So what is the ultimate nullifier?

Aside from sounding like the laziest McGuffin I've event heard, what is this nullifier and what does it do? How does it nullity people? What does nullifying mean?
gpt
It's pretty much what it says on the tin: It is the ultimate weapon for nullifying something from existence.

Once you pull the lever, whatever it is aimed at is removed from all levels of existence. It simply ceases to be. If the wielder is powerful or knowledgeable enough, they can make as if the victim never existed in any and all timelines and universes, as if they never were.

How does it work? Well, apparently the wielder envisions their enemy as completely as they can, in every aspect they can conceive of, and pulls the lever. At that moment, the nullification begins. If the wielder impression of the target is thorough enough for the nullifier to know what it's erasing, it does its job. If the wielder fails to have full knowledge of the thing it's attacking and sufficient focus to see the process through, and only the nullifier knows if this is the case, the wielder can be damaged as well, up to and including mutual nullification- the wielder nullifies themselves as well.

Now the exact mechanism of it's function is unknown. Not even Galactus has ever specified by what means or by whose will the item works, only that it does, even on him, and that is an aspect of his very existence.