The Exact Moment Vi Fell for Caitlyn
Because of Caitlyn and Vi's central romantic relationship, the exact moment that they fell for one another is debated. Here's what I believe.
In the firelight city, when Caitlyn is telling Ekko what her vision was, Vi finally sees Caitlyn for who she is: a caring, good-hearted individual who wants to see both the topside and the undercity succeed. She admits that it's wrong what's been done to those in the undercity and pleads with him for their only shot at making a change.
We can see in the way Vi's eyes soften that Vi is seeing much more from Caitlyn than before. Caitlyn had saved her life more than once in a day, even pleading with Ekko to let Vi go and take her. The scene where Caitlyn and Vi's faces get very close because Vi's in pain from being stabbed show that Caitlyn is returning Vi's feelings, which surprise both of them. And now, in this moment, she's seeing Caitlyn for what she stands for and who she is as a person. And she's falling for her.