Maybe her origin or her past. In the future story, Ais origin, past, and identity will be important to be revealed in the story.

Ais is one of mystery in the story which not yet revealed.

My theory is maybe alfia knows ais past and origin. Ais is possible to be born inside dungeon. She will be used as plot device in the future.

If i not wrong remember, alfia said if Loki familia will used ais as sacrifice in the astraea record. Maybe in the future ais will be sacrifice to defeat monster or dungeon itself.

This is just non sense theory, don't too mind about this and sorry for my bad English language.