A fully functional battle station?

First off: Shut up! Everyone loves super weapons, and I haven't even decided on using one yet.

What has Zayn the Beautiful found in the Croucous Plains (see the map from a previous entry)? Is it a weapon? If so, what sort?

So I want a super weapon that'll destroy a planet, so what? I know its cliche, its a little overdone, but it's just such a useful tool. That's how I see the super weapon, less as a key figure in the plot, but rather as a tool to just get the story started. If the story was only about rebels overthrowing someone, well, I might not be inclined to go to space, to use the other worlds I want to use. With a super weapon, more people, more worlds, more plots, get sucked into the overall story. So the super weapon isn't necessarily a super weapon, as it's a giant super focal point for story. Using the "Big Gun" example, the Death Star was just an excuse to have a couple of pitched battles. If it hadn't been the Death Star, the do or die trying attitude of Star Wars fails.
I suppose what I am saying is, a super world destroying weapon makes the protagonists (and antagonists) move faster, with more purpose because lets be fair, a super weapon doesn't leave you much time.

The idea of a "Builder Race," Older than we can comprehend, has been developed in previous brainstorming sessions. Is this weapon something they used? To what end did they use it, and what does it do?

I have started thinking of the "weapon" as something once used by this Builder Race. Such a device has been a little over used in the past (see Star Wars: Centrepoint Station) but it's not too over used so I am happy with it.

I envision this device as a population subduing tool. That is, these Builders, obviously advanced (most likely physically weaker than their slave races) were spread out over so many planets that they needed a device capable of inflicting a sliding scale of damage on specific - or all - planets so as to ensure local populations kept towing the line.
Think of it this way: Its like holding a hostage and promising that hostage will live as long as everyone just stays cool. As long as the slave populations stayed cool, no one would get hurt. As a result, this weapon can pinpoint regions of a world, or all of a world, or multiple worlds as is needed, inflicting varying degrees of damage. An ideal weapon for these Builders.

An equally ideal weapon for Zayn, assuming human expansion has hit a large enough number of these builder worlds (which who knows, maybe it has). Non-affected populations might be concerned about action simply because they are afraid of killing another world.

How does the weapon work though? What does it do? I wrestled with a few ideas, discarding a lot of them. What I settled on was a sort of gravitational/magnetic field generator, capable of altering the gravity in an area as small as one kilometre wide. The idea is, you could apply so much gravity to a region that everything in it implodes upon itself. Imagine the human body suddenly weighing twenty or thirty times what it does now. Furthermore, imagine that inflicted on a planetary scale, where Earth is suddenly much denser than it was a minute before, and it begins to buckle and crunch, shifting, wobbling, the moon pulls closer, all sorts of things. Very nasty.

So that's where I've left it. A crowd control weapon on the planetary scale, and Zayn is pretty sure its control systems are on Talaesia. Look forward to tomorrow, I think I might talk more about the Builder Race, and probably the Shivasii aswell.