Though she said it as a casual warning, like it was no big deal, the truth was that Seth's ability to regenerate twisted her insides and made her believe that she might just be fighting an immortal.
The first time Seth had regenerated both his arms, Tera had been surprised but had been able to keep her feelings from showing.
Now, though she was still able to keep her thoughts to herself, her mind was forced to come to terms with the fact that perhaps regrowing his body parts and recovering from any injury was but a hand wave away for Seth.
After seeing how badly she had injured him after their first collision, Tera had held out hope that she could do it again and this time be able to make use of the advantage, but her next exchanges with Seth were telling her that that wasn't going to happen and that her initial win might have just been a fluke.
