I know that the Nemesis is not being added to the game anytime soon, but I have decided to give my thoughts on the current "lore". (Information taken from
https://wiki.arcengames.com/index.php?title=Lore:Zenith_Lore_Rambles as well as
https://www.kickstarter.com/projects/arcengames/ai-war-ii-0/posts/1762476 So what I've read is that the Zenith are pretty much non-violent, I guess. They are very much above us and have been around for several billion years. The Zenith don't really have a motive for doing anything. From what I know, they do what they do because that's what they do.
Normally you think of them as these floating things, almost neutral to everybody. Either
neutral neutral like the Zenith Trader or
hostile neutral, like the Devourer Golem (or flip-flopping like the Dyson Sphere). Going around not actively looking for battle or conflict (The Devourer eats stuff, but only when ships/structures are in its path. Pretty sure it eats them to power itself, hence the vamprism.) The Mining Golem from Classic also comes to mind. It eats planets and doesn't really care for anyone else. It doesn't even kill any ships when it destroys the planet and only attacks when a human ship gets near it. So the Zenith are very tame in regards to viciousness compared to the other hostile factions.
But the status quo is broken with the Nemesis. Based on the Kickstarter description of it, the Nemesis is actively trying to hunt Humanity to extinction. Now it's not allied to the AI either, since it "redeploys" AI ships to fight for it. This really blows my mind. A Zenith who actively goes out of its way to destroy you (and the AI)? It makes sense in a way. The Dyson Sphere sits there and sends out ships to defend it, the Devourer roams around eating ships to fuel itself, the Trader trades, and the Mining Golem eats planets. It seems that every one of the Zenith has a set role. Makes sense that one of them has a military purpose.
Basically, it brings a welcome change to a very stoic, unfeeling, and passive/defensive race. Having a planet sized Zenith saying "I'm going to murder Humanity", in my opinion, sounds like something so out of character for a Zenith that it sounds right. It provides another angle to the Zenith. Maybe they do have emotions after all. Or maybe that's simply what it does, like all the other Zenith that Humanity has encountered.
