Lots of headcanon.
After inheriting her mother Rhinedottir's legacy, Vikali silently gazes into the darkness of the universe, lost in thought.
"Can my alchemy really do anything about this?"
In an earlier timeline, Ming Zheng looks at The Foul, who is eager to fight, and marvels at this absurdly overpowered matchmaking system.
"First a prophet, now The Foul. What on earth is this trying to do?"
In the darkness, little Huayin laughs as she watches the endless Abyssal forces fighting among themselves.
In the final timeline, Alhaitham, now a Great Sage, remains silent for a long time as he looks at Alhaeno, who has abandoned his original body and is now covered in Abyssal power.
"So, are we still related by blood, my dear little brother?"
"I guess... we are?"
In Fontaine, the All-Devouring Narwhal never imagined that a machine from a place with technology far beyond this planet's could toss around the mighty star-devouring beast like a rag doll.
As the darkness draws near, even the undying Qiye falls victim to the matchmaking system. He looks at the darkness of fate before him and asks a question from the depths of his soul.
"I'm fighting the darkness? Is this for real?"
I'll start another storyline about the worldbuilding after Inazuma.
There's Lovecraftian horror, but it comes later.
I'm no good at writing summaries. Go read the story.