Using the current version of the game (win64 Version 123, unmodded) I obtained Zephyra for the first time, using the enslave option. I did not realize the mansion was full at he time (15/15 people). This caused Zephyra to be permanently unavailable with a status "Relocating: in 1 turn". Even though she is assigned a trainer, she is permanently resting and not inside any of the game locations (in the "Characters on the road" category).