[Spoilers] Why Zenos is the most important character moving forward

[Edax]

Actually, the reason we can argue until we're blue in the face is because what we're arguing about is SUBJECTIVE, not OBJECTIVE. Different people have different ideas about what constitutes good writing. As evidenced by this very thread, some find Zenos to be a very compelling character. You and I do not; we care about the story and are worried that it will be lessened by setting the guy up to be the primary antagonist - but that does not mean that they are WRONG, or that you and I are RIGHT. The Edax Test, no matter how you edit and re-edit its text, is fundamentally nothing more than an expression of your personal opinion, and one I believe to be unhealthily wrapped up around a specific instance. Perhaps you'd change your mind about the test if you found the right story to use as a counter-example, or perhaps not. Regardless, your test is applicable to you and you alone. Others may agree with it, but that is purely a matter of their opinions meshing with yours, and not indicative of any kind of fundamental truthfulness of the test. The Bechdel Test, for its part, is purely objective. Any two people reading a work will give you the same answer as to whether it passes or fails (barring weird fringe cases, like having one of the women be a hallucination by the other, or something). They may disagree on what the results of that test MEAN, but the test itself is entirely divorced of personal opinion.

Craftsmanship is measured objectively, not subjectively. Everyone has different ideas on what constitutes good writing but we understand that most 5 years olds aren't capable of making objectively good writing. This is why writing is taught in school because it is an objective skill. We can identify the lack of Zeno's characterisation or his lack of relation to the story objectively. Whether you enjoy Zenos is subjective. How you feel about Zenos is subjective. But how well written Zenos is can be measured. The story should be mechanically sound.

The supporting examples you've provided also seem to be trending toward the questionable assertion that "well written" is equivalent to knowing so much about the character that we can accurately predict what they will do upon achieving their goals. Readers don't always have that kind of omniscient viewpoint, nor is it a requirement for a work of literature - or the antagonist within it - to be well written. Very compelling antagonists can be developed, for instance, by knowing only what the protagonist knows about them (which, of course, is the general rule in stories told in the first-person). The protagonist could be biased, or outright incorrect in what they know, or they might not know the antagonist well at all. In such a situation the reader, too, will be biased or incorrect about what the antagonist would do if they destroyed the protagonist. It's not the author's obligation to tell the reader what the villain had for breakfast, nor does failing to do so lessen the quality of the character.

Very well compelling antagonists can be developed in a story and used effectively, but the absence in writing of that antagonist disqualifies it as "well written". How the protagonist perceives an antagonist, would be character development of the protagonist, not the antagonist. With a 1st person perspective, the antagonist could be a hallucination that might not even physically exist. But in cases like this, what your looking at is the psyche of the protagonist.

You could argue that early in an antagonist's development, that character is not well-written, but as the character develops it BECOMES well-written - but I feel this is basically just redefining the term to support your case. It may be irrelevant in Zeno's case, as the writers SEEM to have already laid all of his cards on the table (I would argue that there is room for further character development, myself), but when stated as a general rule for all works of literature, it becomes tougher to swallow.

I'm sure fundamentally you are right in that I have no authority over literature. I only sought to provoke a thought experiment.