We can assume based on Yohualtecuhtin‘s behavior that Columbina completely lacks an ego, and will probably undergo similar character development

The Lord of the Night is probably the most selfless character we’ve encountered in Genshin so far: when Capitano tries to sacrifice her she agrees without hesitation, and when he later comes back to her to fuse his soul with her body she doesn’t hold any ill will towards him and becomes a key figure in Capitano’s revenge against Ronova: this behavior is explained by her being an Angel, as angels are always supposed to take humanity‘s side no matter what.

Citlali and Xilonen get moved by her extremely selfless nature and offer her a way to extend her life, but the Lord of the Night replies that her life is meaningless as long as humans survive, as Angels must only serve humans instead of having desires for themselves.

After Capitano‘a sacrifice and her newfound immortality, she is immensely grateful for his gift and apologizes for thinking so little of humans worrying about her well being in the past.

Assuming Columbina is an Angel/Seelie, she will probably undergo similar development: initially a Fatui killing machine for the sake of “humanity” (the Fatui are explicity called the “human faction“ that the Traveler must face), she will start thinking more about her well being after her experiences with the Traveler.