Disclaimer : I do not own Manifold Trilogy or Worm. They belong to Stephen Baxter and Wildbow respectively.
Blink.
Geador grew aware oh his surroundings. But his abstract form was disconnected from reality,
'As usual' he muttered.
His consciousness, previously encoded in lightyear-wide wispy atoms was now no more, but it regenerated into something not bound by physical laws.
Yes, after Vacuum Metastability Event which destroyed the Manifold of infinite universes, Geador and his fellow Downstreamers in the Conflux managed to survive in some form.
Eons were spent by the newly-ascended Downstreamers in nurturing multiple Manifolds, modifying the very underlyings of reality, rewriting the governing logic and mathematics to create new infinite possibilities for life and mind.
The Downstreamers didn't make half hearted efforts in ensuring the diversity of lifeforms, and for them to flourish.
Refugium, universe-spanning construct made of cosmic strings built to preserve life all across the cosmos.
Planetarium, simulation system that protects primitive inhabitants from cruel outside world.
And Red Moon, a planetary construct built by the Downstreamers for the purpose of distributing and promoting hominid lifeforms across the multiverse.
And the one of the Red Moons had caught a peculiarity in one subset of a Manifold. A peculiarity in the form of a threat to diversity of lifeforms.
The data feed by Red Moon was received by Geador. The data was read, and processed by Geador, thanks to infinite computing power that comes with Downstreamer physiology, it ended in no time.
Geador saw, and got a grasp of the threat. A threat that spanned across large number of universes, leeching off energy from an entire subset of Manifold, for the purpose of completing their 'Cycles'.
Geador decided to call the threat : 'Entities'.
Geador felt annoyance at them. Conquering other civilizations, turning other civilizations' technologies and accomplishments into 'Shards'.
Geador had nothing against sentient races trying to survive in cold harsh universe. Geador could even see the parallel between his race, Humanity and the Entities, in which both were fighting heat death. But it doesn't change the fact that the Entities' way of surviving costed too much of diversity of lifeforms. It has to be rectified.
And so a Time Portal was created at a certain universe on the subset of the Manifold, following his will of the containment of the Entities.
The Time Portal formed near a random supermassive blackhole. And Geador 'passed through', a nostalgic view of event horizon greeted Geador.
'How nostalgic indeed' Geador thought. Before the heat death of the Downstreamers' native universe, in the Black Hole Era after all stars have been extinguished, they built Mines, comprised of artificially grown blackholes which massed over hundred trillion solar masses, all moved across the universe to be used as cold hearth for the Downstreamers.
But Geador stopped reminescing, and set out to work. His mind, comprised of Causal Loop computer gathered data from the future and the past, in order to run perfect simulation that'd include all possible states a universe can take, down to quantum level.
Then an omniscient database was formed not long after Geador's subsequent arrival. Then he created many more Time Portals all over the subset of Manifold, and Geador gathered more data, all possible configurations of all universes within the subset. Then Geador planned a countermeasure based on the data he had gathered.
Geador reached upon an empty static universe, infinite in size and infinite in time. A universe engineered to be truly eternal, in which the fear of heat death is but a childish nightmare. A perfect habitation in which the Entities could live, but couldn't escape.
He reached into Phase Space, a sea of possibilities of all universes within the subset, and reweaved the lines of possibilities, which warped all universes within the subset of the Manifold following Geador's will.
The Entities', for all of their defense against dimensional intrusions, were powerless against the power which shaped the very basic concept of 'possibility' itself. Their Path to Victory rendered null and void, because Geador's omniscient mind already included the mechanics of Path to Victory, and flawlessly simulated it.
Entities' population all across the multiverse, across all different timelines were 'rounded up' into the eternal universe. Their gigantic forms which normally were too large to fit inside normal finite universe were forced to manifest in their glorious unbounded form. But no matter how large Entities' forms is, it is still finite. And finite scale, no matter how large it is, is trivial in front of true infinity.
And rendered trivial the Entities are. Geador modified the Phase Space, erased the possibilities of Entities from ever being able to contact outside the eternal universe from the storage of possibilities. Essentially locked the Entities away inside the eternal universe, for eternity.
And then the subset of the Manifold underwent a great change. Without the Entities' Cycles ruining the continuement of all spacefaring civilizations, many civilizations can continue to expand.
All iterations of Earth on the subset were changed, with no Entity showing up to complete their Cycle on the blue planet.