If you're wondering where the next chapter is, I have writer's block, in the meantime here's a list of who is paired with who

Demoman-nora
Sniper-ren
Soldier-jaune
Medic-pyrrha
Spy-blake
Pyro-yang
Scout-ruby
Engie-weiss
Heavy-coco
The reason I'm having the mergers happen when they're young is for them to be fully merged by the time season 1 rolls around