(I'm a veteran Arknights player, especially fond of Exusiai and Kal'tsit. Some characters in this book may be out of character, but this is how I imagine them, so please don't flame me if you don't like it.)
What if, during the Babel storyline, the Doctor had chosen Terra rather than the Predecessor civilization in the trolley problem? Would the story of Arknights have reached a different ending?
In this story, changes to the timeline will prevent tragedies caused by helplessness.
Theresa, FrostNova, Alina...
None of these regrets will come to pass. They will all survive on this land and continue their own stories.
Of course, in this book, our Kal'tsit, our little Kal, will no longer be the all-knowing Kal'tsit I know. She'll simply be the Doctor's eldest daughter.