FGO is very obviously not ending. It's up in the air what the next story arc will be but it seems pretty likely they're touching Notes

>A story that describes the extermination of humanity, and the war between the new humans and the planets. Its genre is science fiction.
>It recounts fairy tales of the war between the new humans, who adapted to the environment, and the A-Rays, who came from the artificially created next-generation ecosystems. On the planet that was doomed to death, political strife developed between the two races, to the point where the mysterious beings, the Aristoteles, rushed over from the universe with the intent of completely wiping out all life---In any case, ultimately it is a hopeless story.