Most non-Illuminated Lunars rationalize the Red Goddess’ association with Chaos connection by reasoning that she makes use of Chaos so that she might confound and defeat her foes. We’ve heard countless variations of this from various Lunar supporters. And this is not wrong.
But many of her foes view her as a harbinger of Chaos. A herald, that signals the resumption of the Chaos Wars. Her appearance opens the way for Chaos to return into the world and once it returns, it will not be controlled by anything. This too is not wrong.
That’s the complexity of the Lunar Way. The Red Goddess is a rabbit-duck. She is BOTH the one that has managed to use Chaos to liberate her people from an evil empire AND a tool of the powers of Chaos. The user and the tool simultaneously.
See also:
if Chaos is not inherently evil, what is it that corrupted chaos in to the form it exists I’m Glorantha, is it a flaw in the Chaosium it self?
Outside the cosmos, all is Chaos. Or the Void. Or raw possibility. Use whatever simile you want. The cosmos came out of Chaos in pretty much every Gloranthan origin myth. But at some point Chaos tries to reabsorb, devour, silence, whatever the cosmos. Where it enters the cosmos, it corrupts, both physically and morally. The cosmos is twisted, turned on itself. Virtues becomes vices. And so on.
Chaos threatens us with non-existence. For some that twists them with rage and hatred at their own existence (e.g., Thed), for others that removes any limitations on doing whatever the hell you want (Thanatar, Cacodemon), for others it is something to serve (Krarsht), and for others it is something you avoid by sacrificing others to that non-existence (Crimson Bat, Vivamort). And so on. This is the Great Terror.