Sources function mostly the same as "Dependent Concepts", except that they govern a living thing's entire existence across present, past and future, but I'd rather not debate what type of concept sources qualifies as atm.
I was under the impression that characters who were NEP Type 2 with the previous standards would be Nature Type 2 with the current standards.
I apologise for the confusing explanation then. I'll try to explain it better.
Graham has a "normal" source, like all other characters. Once that source is destroyed, his Source of Nothingness remains. Indeed, his Source of Nothingness is the lack of his normal source, which is why his Source of Nothingness doesn't function like other sources (he no longer has a body, soul/spirit, mind, or even existent magic power, despite having this "source"). This Source of Nothingness is definitely completely nonexistent tho.
This Source of Nothingness can be further reduced to nothing as well, after which a pure nothingness remains, described as "nothingness without reason/logic".
As far as I know, you can keep destroying this nothingness and further reduce it to nothingness, but as long as there is nothing, Graham will be able to reform his existence again. (This isn't the case in the presence of
Venuzdonoa tho.)
Anos' source isn't literally nothingness like Graham's Source of Nothingness. His source is fused with Graham's nothingness, so if someone wants to interact with his source, they would first need to be able to interact with Graham's nothingness, which is why the novel describes it as using the nothingness as a "shield". This isn't activation based as far as I know.
I would personally be fine with Nature Type 3, Aspect Type 2 for Anos' source, because it seems to fit the following description: "Characters still exist, but paradoxically behave as if they don't when attacked."
No. My actual argument is that if it's consistently stated that a type 2 concept is the most fundamental aspect of a character's existence and that there exists nothing beyond it, then it would be incorrect to assume there does indeed exist something beyond it, like a type 1 concept.
Using your example (which seems like a false equivalence IMO), it would be more so that in a verse where it's consistently stated that the body is the most fundamental aspect of a character's existence and that there exists nothing beyond it, and yes souls were never mentioned, it would be incorrect to assume there does indeed exist something beyond it, like a soul. Again tho, your example seems like a false equivalence, so I can't properly support my argument using your example.
Anyways, why would it be automatically assumed that characters have a type 1 concept, despite it contradicting the story?