Interesting.
So I guess these guys are employed void/neverborn-type chaps who want to end the world as we know it? I'm unfamiliar with L5R.
Who do we go to for this? Because it sounds way above our pay grade. (Which also means it's something we can use to increase our pay grade, so that's something to keep in mind.)
The Lying Darkness. How to explain the Lying Darkness. Hmm.
We had a play about them earlier, so that might be a good starting place. (Foreshadowing.) The primordial void, where nothing existed, felt; and in this feeling it was no longer void. From that feeling came Lord Moon and Lady Sun, and they created the world and all that good stuff. Yet as they went around, naming things, the void remained, and the void...well I guess the best way to describe it is the void is metaphysically inimical to everything of substance just as everything of substance is metaphysically inimical to it. Even nothing, in the world of substance, is technically something. The Lying Darkness, however, is truly Nothing. Once everything was Nothing, and the Nothing would see the universe that way again.
During the creation of the world, it cloaked itself in shadow to hide while everything was being named (or it convinced Lord Moon not to name it, offering him a back door towards unmaking his creation if it became necessary), and thus in a fundamental way is not bound by the rules of Rokugani cosmology or the laws of nature. It can do things that should not be possible, interact with reality in ways that do not make sense. It works towards the unmaking of reality; but it has the patience of an immortal, and is not in any great rush. In mode of operation it can be infinitely subtle, or savage beyond even creatures of the Shadowlands, by turns. The Nothing is out to destroy not just the physical world but the metaphysical one, and at that level of do-not-care savagery is almost inevitable.
Those infected with the Nothing gradually lose their self-will and their identities. At this point in time, concepts like "families" of the Nothing's servants haven't yet developed (the Nothing is barely known to Rokugan at all, save ironically to us of the Scorpion and we're probably not privy to that, and to the Kolat), and in any case none of its servants have any kind of self-will at all until post-Volturnum, which hasn't happened. True creatures or agents of the Nothing possess no free will or mind of their own even in the perfunctory way that someone Lost to the Shadowlands appears to; this does not mean that they are unable to reason, but they are effectively remote puppets for the greater Nothing and have no individuality in terms of reasoning or behavior unless it suits the Nothing to make them seem as if they do. They can assume the form of a normal Rokugani, to greater or lesser degrees of skill depending on their relative level of power, for greater or lesser lengths of time.
Basically, this is a really good time to start hoping Pale Oak
is Kolat, because they might be able/willing to help.