>>527445506
It doesn't have to be a Darkner.
The wording is specifically
>The Third Hero, the Prince, Alone in Deepest Dark

>>712577839
Could also be that she was meant to hide herself for the adventure. Like keeping it a secret who she is from Noelle since Noelle would still be looking for her sister.

It is a very popular trope to reveal that the mysterious character was actually the family of the main character.