Capítulo 159: 3.07.04 Confrontation.

A simple slip was all she needed, the knife had already penetrated Krotal's neck and with a bit extra motion, it would be severed, killing him in an instant.

To her, the end justifies the means and from the looks of it, the whole fight was going to turn for the worse for her group. From the words of these two parties alone, she knew that it wouldn't be long until they singled out Max and attacked him together to eliminate him. Which she won't let happen.

So, even though she had tried to save Krotal's life before, now she wants him to save her and Max's life. Which he can only do by turning into a Hostage, like how it was planned from the start.