The issue with the "Edax Test" is that it operates under the assumption that the villain has a plan.

Villains like Zenos do not have plans. Zenos is like the Joker - a dog chasing cars, who wouldn't know what to do if he caught one. He doesn't have a plan or plot beyond getting a satisfying fight. He can't "progress the story if he wins" because he has no stake in the overarching mythos driving everyone else.

As a character, Zenos is very boring; as a plot element, decidedly less so. (Pointing out which was the reason this thread was made.)