Honestly, Kafka's and Trailblazer's relationship is something I can't wait to see Honkai Star Rail explore more of down the line. She's akin to a mentor, but both characters actions and attitude towards one another suggests otherwise, or that it's even more. And various characters have commented on the seemingly deep and unique bond that the two of them share. Not to mention the two's intentions (especially Kafka's). Kafka's greatest desire or wish, is gaining the ability to feel fear (something that she and everyone else from her home planet are incapable of feeling). It's suggested in Kafka's companion quest that Kafka will achieve her goal with the Trailblazer's help.