What exactly is the main motivation behind Shivan omnicide this time round? Is it due to the Sol-GTVA war? Or because they're worried Ubuntu (+ the Vasudan's guiding philosophy) will bring forth manifold necrosis/Great Darkness?
They oppose. They destroy. In destroying the create the possibility of newness, and prevent the total hegemony of any one thing or meta-thing. This is not their purpose: they have no purpose. But it is their effect.
When Bei sees the Shivans saying "they are like us, they destroy" it's not just a moral judgment upon humanity or the Vasudans. It's an inability to even recognize the values the Vishnans assert. The Shivans don't say "they're bad at creation" or "their old wounds open all too easily" because those aren't really relevant factors to the anima. What's important is that they destroy. That's the only real thing.
But when you look at it that way, you can almost see it as a sign of approval. The anima evaluating humanity as consonant with its way, not the Vishnan way.
The Shivans are anathema to the Great Darkness and resist its creation/spread at the most basic level. But they can only make large-scale plans or schemes against the Great Darkness if an anima can hold on long enough without being torn apart by the very nature of what it is. To the extent that Shivan omnicide has a 'motive' under this anima, it is simply to do what the Shivans do even better, more completely, more thoroughly, without restriction.
Shivans can't go universal genocide because of the Vishnans and some 'council', I thought? Like, that's what's stopping them and from what it looks like, the Vishnans can easily give Shivans a run for their money. Same with life perseverance, that's Vishnans wanting to do that because living is sometimes cool and getting rid of people ain't that swell.
The council is the terminal protocol is the dying design of the Brahmans: a set of strictures which the Shivans and Vishnans obey in service of the ultimate goal, a return to the greatness of the Brahmans and an end to the Great Darkness as a threat. But every aspect of that last sentence is subject to the constant assault and corrosion of Shivan metacognition. Any aspect is open to challenge.
The Vishnans do have one great advantage over the Shivans—they are in a higher, more removed position, outside and above of events. This is also, of course, their great disadvantage.
The Shivans are omnicidal, but they are not preemptively omnicidal. They do not attack or deplete the resources which give rise to life. A universe swarming with Shivans is not a universe of reduced diversity, exhausted subspace networks, or dead worlds. It is a universe full of fascinating and infinitely varied tombs: each species risen into the void left by the last, each extinguished by the Shivans.
Seconded. I would add to that, "If GD/Manifold Necrosis is what the Shivans are concerned about why don't they just exterminate all non-Shivan life and sterilize every planet with life on it or potential to produce life at some later point.
How would this goal arise among the Shivans? Who would pursue it and see it through? How would this goal endure in an environment so terribly corrosive to any stable behavior or purpose? What if it is regularly attempted by the Shivans, all over the universe, and the life we see is simply what slips through the cracks? Everything that lives is that which has failed to die. In an infinite cosmos, anything less than a 100% extermination rate still produces an infinite number of civilizations to rise and challenge the Shivans. Each one will ask itself: "Why are we here, when so many others were destroyed? What gave us this chance?" And the answer is: the very same chaos and blind arbitrary violence that will one day wipe them out.
Of course, the Vishnans inject their preferences and manipulations into the process. But they too are subject to the corrosion of the anti-being.