Ugh, this seems a really distorted description of the conversation. The existence of those entities is not why they were brought up, at least not by me (and again, you all are ignoring the Morrígan, in open disrespect to her and her followers). In fact, some or all of them “exist” in certain ways, and in at least one case (Nessie) it remains technically “reasonable” to speculate about her existence without any reference to the supernatural. The point is about the logic applied to anyone’s skepticism about the Morrígan or Loki or Yahweh. This should be obvious, but to make it even more obvious, let’s just assert that the Morrígan is the uber-god that we keep hearing about, this “necessary being.” Of course I can equivocate and say that the whole “necessary being” thing is really a post hoc solution to a manufactured problem, but I can also say “yay, not only is the Morrígan fierce and brave and worthy of devotion, not only is she a trinity of women instead of the lame dudes of Christianity, she is now the [checks notes] necessary being that [checks notes] must exist. HAIL THE Morrígan!!!”