Rebecca had grappled most of this truth a long time ago.
When Akiol revealed to her that he had taken over the body of her brother after James had passed away. . . she admitted there was a part of her that didn't quite believe that. Perhaps her brother had lost his mind in the time he was away.
However she had seen just how suddenly incredible James had become. When he challenged the Tower of Strength Extremity, and managed to complete it in one try despite her struggling with it for months it really made her doubt if she was speaking with her actual brother.
James was never that capable.
So when Akiol came clean it really did make sense. After all that could be one extreme reason as to why James was suddenly so capable. When they dealt with Withered Oaths, and despite the real threats they experienced Akiol had remained calm and helped them through.
When Rebecca saw the ordinary yet exceptional people he brought along, his story was given more credibility.
