For fairness sake, I changed 2747's key to Extended Canon. It's not a stomp because like I said, 2747's dimensionality depends on what story it is in. So once Altair eventually becomes High 2-A this match is still valid.
>How is he affecting someone that exists outside of the narrative that consists of the entire Re:C verse??
By transcending that construct entirely. When 2747 finishes building up, he will move on to the Narrative above Re:Creators and destroy that and so on and so forth.
>Altair either nulls him, copies him, clones him, info rewrites him conceptually, absorbs him conceptually, fate/probability/causality/plot haxes him, law haxes him, reality warps him, erases him,etc
Putting 2747 down forever would require (something close to) 1-A hax. While taking it out temporarily with better hax is possible, it will just pop up in the Narrative again immediately. So Altair can keep erasing it as much as she wants, but 2747 will always come back because to truly erase it, you need to be above the countless Narratives above it.
SCP cosmology works like this: the SCP Narrative with it's 100, 000+ dimensions is qualitatively inferior to the Narrative above it which can have anywhere between 2 dimensions to infinite dimensions. That Narrative is qualitatively inferior than the Narrative above it and so on. This goes on infefinitely and 2747 would eventually destroy them all. Essentially, if the Narrative above the current one has only 2 dimensions, it is still superior to a Narrative below it which has infinite dimensions.
Altair's win condition here is to keep it out of her Narrative for 24 hours, which is the incapacitation condition. And she has all the time in the world because it took about a few years for 2747 to completely destroy the SCP Narrative.