Having two women talk to each other about something other than a man is a flawed principle for evaluation, inherently unequal in its criteria, and eliminates the possibility of treating women as default with as much respect, attention to quality, attention to detail, and focus on individual identity compared to men. It misses the forest for the trees and diminishes potentially brilliant works and characters for something ultimately insignificant. Men are not subjected to any version of this test and would not have their quality called into question if they failed to meet such criteria.
Having a quota for representation and potentially lowering the bar for representation because meeting that quota takes priority over telling the story effectively hurts representation. This is because a flood of forced, lower quality stories teaches audiences to associate representation with low quality. It's good to include a wide variety of characters across demographics because they offer a broader range in life experiences and perspectives, but they should fit the work and they should have some purpose within the work beyond existing as representation. Anything less is dehumanizing and ultimately hurts representation because the audiences WILL notice what you're doing. The path to success comes from sincere enthusiasm and being treated as normal or nothing. Because there are people capable of delivering that enthusiasm and the depth that comes with normalcy. The more they get drowned out by token characters, the more stigma goes to the represented group.
There is room for stories about just men. There is room for stories about just women. There is room for stories about men and women together. So on and so forth. The arena for sharing stories is open to anyone who chooses to tell them and can tell them well enough. It must remain that way rather than fall to identitarian censorship. That censorship just breeds resentment and further division while limiting options instead of expanding them.
You do not cook. You can understand basic things like there shouldn't be a cockroach on top of your food. You know you like the taste of some things but not others. If you go into a high end restaurant, order something prepared in a way you're not used to and don't like, then tell the chef they did it wrong and don't know what they're doing--you are in the wrong there. You don't have to like the food prepared. It isn't the fault of the chef and doesn't mean something was wrong with the food. If you want to evaluate the technical quality of an unusual food in a high end restaurant, you better know damn well what you're talking about.
Writing is not all about your feelings and how much you do or don't like something. There are different forms of writing between genres and according to whether a work draws from empathy with its characters or wish-fulfillment using stand-ins for the reader. It is ignorant to use the same criteria you would use on I don't know, Paradise Lost, for a bodice ripper.
I can refute your Edax test not only for Zenos but for a number of other characters. Zenos is obvious and easy but doesn't address your entire principle being flawed.
Zenos killing the Warrior of Light doesn't mean anything more than he needs a new rival and the Warrior of Light no longer meets his needs. It's just that simple. He does not care one bit about the Warrior of Light as an individual person, as I've said repeatedly in this and other threads. He cares about someone being strong enough to beat him. It could be literally anyone and he would be just as excited. Right now, the person he found is the Warrior of Light. If the Warrior of Light is dead, he needs to resume his search. He won't mourn us as a person. He'll mourn that the role is empty again. He is driven by very few, very simple desires but he will pursue them ruthlessly and remorselessly. There are people like that. Part of how empathy-based fiction operates involves reflecting the human experience in some way, shape, or form. This is a type of human experience. It operates with clear and understandable cause and effect motives. It is shaped by the environment it interacted with from birth and a series of experiences, all effected in-turn by born personality. It is nature and nurture both, consistently and cohesively.
We could easily have a story about the Scions struggling to deal with Zenos as he searches for new quarry while trying to fill the void left behind the Warrior of Light.
Now lets try a hypothetical villain who fails your Edax test. Lets say that the arc of this villain involves them deteriorating over time. Like Macbeth. Lets say that the villain begins as a person of decent or middling morality, but extremely low self-worth coupled with isolation. The villain is treated to a small kindness by our hero. They latch onto that and spiral deeper and deeper into obsession. Eventually they can no longer imagine life without the hero. They stalk the hero, kill competition for the hero's attention, kidnap the hero and keep them in a basement.
The hero tries to escape and, in the scuffle that follows, the villain kills them by mistake.
The absolute lack of self-worth remains, but now added to this the villain also realizes that this one person who did them a kindness, who let them feel for a while like maybe they were worth kindness, is dead. And it's their fault.
Villain commits suicide.
Boom. Technically fine character and variations off of this concept have been around for centuries. Character is tragic, has a clear arc, has motivations throughout.
Characters do not become ineffective because they are personally weak. This is part of the human experience too, and knowing that it is a possibility furthers suspense across the board because it lets audiences know that it is possible for heroes to fail. This lends weight to every victory. It's why it's important that we as the Warrior of Light lose to characters like Zenos and Ran'jit. It's why it matters that the Fuath nearly drowned us and Emet-Selch nearly turned us into an unstoppable sin eater. When you never fall and never experience vulnerability or weakness, you not only lose perspective and dramatic tension--you lose the sense of humanity that allows audiences to relate and invest. Because human beings are sometimes weak and sometimes fail. It's part of why heroes who manage to succeed despite this threat are so inspiring. They're willing to face those stakes.
I've been seriously trying to be nice to you with this. As I said before, I don't care if you don't like Zenos. This is a measurable craft and it does have objective elements not related to mechanics like spelling or grammar. Your feelings and individual preferences will not make you more right about technique.