I have never too fond of how future humans are portrayed along with aliens in books and movies. They just seem too relatable. But I know if they have to be because if they weren't the story wouldn't be so interesting. But I just hate aliens attacking earth and humans winning, wtf is that? The universe is too big for that but war is pretty fun to read and watch so I can understand. But anyway...
The idea is that it takes place hundreds of millions of years into the future. It starts out on this planet with a devastating war going on. You kind of assume it is humans because they are pretty relatable to who we are now as a species. But they have invented the technology to destroy themselves and are carrying that out. Their planet is becoming uninhabitable from how they affected the environment irreversibly.
Then this alien ship arrives which appears to be an incredibly bright star just outside their solar system. But it is actually future humans on the ship that have progressed and evolved to a point of... I guess perfectness? The gigantic ship is a giant sphere ( Many times larger than the star that the aliens orbit around). It houses an uncountable if not infinite amount of humans having layers of layers of unknown material keep it together. It is powered by a black hole in the middle which allows them to bend space and to travel great distances to find Stars to fuel this black hole power source.
The reason they ended up here is that the aliens planet is orbiting a star that is the right size mass etc. to fuel their black hole generator. The future humans do not control the ship, everything is done by quantum computing or something even smaller that allows them to CREATE ANYTHING they want within the spherical ship. Bending space and time and the laws of physics of the universe into anything they can possibly imagine. (So many cool ideas for the humans massive ship).
The thing is the ship disappears from view and goes to start absorbing the aliens sun by just consuming it. It takes awhile. But the cool thing is, is that these future humans have never seen intelligent alien life (which is rare) before. Only the most simple forms of life on very few planets they come across.
The reader and/or the aliens may not know that their sun is being destroyed, just that these future species have showed up. From this point the humans are helping the alien planet deal with its certain destruction. Repairing and terraforming the planets environment, water, air, ozone, people, and perhaps screwing up in between because this situation has never occurred before.
Many aliens are overjoyed on that they are not alone in the universe while others are scared and skeptical (I'd base this with what I think how humans would react to this situation). In the end many alien lives are lost from the wars but the planet will be habitable. At this point the Humans reveal that they needed that certain sun of theirs to keep their ship going.
It is incredibly devastating that the alien life is left to die. But then again the aliens ask the humans, can't you take our planet with you, can't you take us with you? But comparably speaking the humans intelligence to the alien's is like a human compared to a mouse. And that during the time they were absorbing their sun, they used their quantum computers to process the whole planet and every detail down to the smallest particle in the universe. Sort of making a copy of them for storage on their ships archives. And in their ship they can predict an infinite amount of different ways of how the planets and species on that planet would play out making no sense of taking them.
So the end would be the aliens dieing off on their cold planet thinking of them as gods and or destroyers. The whole book would be taken mostly from the aliens POV because even how much detail I want to give the humans, since I am not a super future human like them I don't want to give them an unknown, stupid, relatable, personal meaning behind them.
I just love how this idea has a lot of potential and I love thinking about this kind of stuff and seems very different from many mainstream ideas of how aliens interact with humans. But instead the humans are considered the 'aliens'.
