The first Luminai emperor does make sense. He was sent as both envoy and symbol, bearing the technology of the Eldan and the obvious unity with the Cassian humans. And he was the one who started off on the process of forming the Dominion, of getting Cassus on board with the idea of going out and spreading "galactic diplomacy" to every species of at least mild sentience. He had a purpose.
However, there have been more emperors, more Luminai, and they haven't served a function that couldn't be provided by the Mechari.
Let's take a step back to the origin story. If the Eldan had sent the Mechari laden with technological gifts on the condition of forming an empire, can you really say the reaction would have been all that different? Odds are nearly absolute that the net results would be almost identical, just with a bit more debate over who gets to be in charge. The Luminai weren't what made that initial pitch work.
Nor do we have any reason to believe that the Luminai have some special insight into the plans of the Eldan. Despite fiction sometimes playing with this idea, children do not generally know exactly what their parents want or thought. And if you assume the Eldan wanted some people in place specifically to manipulate or control the situation, again, they already have the Mechari. Creating a hybrid race with full knowledge of the Eldan Master Plan seems like much more work than just programming your robots to work with it in the first place.
All logic points to the idea that the Luminai are not a byproduct or a part of the Eldan's overall plan. Whatever the Eldan want, the Luminai are a core element. They have to exist.
So let's go far afield and start positing a few things. We know that more Luminai have existed after the first; we also know that the first one was the only one directly created by the Eldan. It's reasonable to assume, then, that the Eldan blood is "thicker" than human blood; quite possibly the offspring of a human and a Luminai will always be a Luminai. The alternative makes no sense, since if there were any gaps wherein there were no Luminai offspring, the Eldan wouldn't have been able to introduce one for a thousand years now.
Logically speaking, at this point you're looking at a dynamic similar to that of the Japanese dynasty. Rather than attempting to overthrow the Emperor, would-be rivals had as their predominant goal to marry children into the imperial family, slowly intermingling their family's bloodline with that of the imperial bloodline until said family has effectively become the ruling body. Similarly, no one attempts to overthrow the Luminai. But things get interesting if you assume that a sitting Emperor has more than one child. There are multiple Luminai running about. Or perhaps some of them are outwardly human, producing offspring that still have some of that Eldan blood floating around amidst everything...
What if that is the ultimate goal of the Eldan?
Suppose, for a moment, that some sort of calamity befell the Eldan as a whole. Maybe we can assume it's some fundamental weakness of their biology, something that causes the population to shrink and eventually no longer be viable. Or perhaps it's an understanding of some underlying force that simply resists the Eldan, magic of some variety. As a people, the Eldan cannot allow this weakness to persist.
What if the Eldan are entirely capable of taking over the Luminai when they so choose? What if the Luminai are meant to serve as receptacles?
It would take time, experiments, and work. Research would need to be done. A race would need to be found that could fix whatever problem was present in pure Eldan specimens. That race would need to be kept away from Nexus while the groundwork was laid; the Eldan couldn't risk appearing weak or incapable. And when the Eldan returned through their errant offspring, they would want a structure in place... a galaxy that already bowed and scraped by proxy if nothing else.
I asked before why the Eldan would care about establishing an empire that they did not intend to be a part of. But perhaps that's the point. Perhaps they do intend to be a part of it, to take over in the bodies of half-breeds. All it takes is a tiny fraction of the Eldan's blood and you are close enough for these aliens to make you a host... and no one at the bottom would ever notice the difference.
Feel free to leave feedback on my latest crackpot theory in the comments below or by mail to firstname.lastname@example.org. Next week, if you're tired of my various lore natterings, you'll be happy to know that I'll be moving back to system speculation by talking about transportation.
Here's how it is: The world of Nexus can be a dangerous place for a tourist or a resident. If you're going to venture into WildStar, you want to be prepared. That's why Eliot Lefebvre brings you a shiny new installment of The Nexus Telegraph every week, giving you a good idea of what to expect from both the people and the environment. Keep your eyes peeled, and we'll get you where you need to go.