My take on Zenos, is that he was basically used as a foreshadowing device.
A lot of the civilizations that Meteion came across are very similar to Zenos. They are one-dimensional, and it led to their own demise.
They couldn't find a purpose in life anymore, and felt the need to have a purpose (being the strongest, being the smartest etc). Just like Zenos.
After our fight with him, he literally admitted that it led him to suffer some form of depression.
It's the whole theme of the expansion.
And that's the reason why I liked him in EW. Not really as a character, but as a plot device.

Now...I still want him back. There are still things we need to learn about him, about what he is, but also about what his avatar is.
To be honest, there is no reason to believe that he died for good, so I would be surprised if we don't see him again...