If people were to simply sit aside and let them have their way, what do you think would happen? You just said you had no qualms with allowing Kaname to follow through with his plan. It doesn't stop at Sara, you know.
[Her jaw tightens.]
As a consciousnesses person, I won't sit aside and allow Kaname to cruelly murder or hurt anyone else! And Zero - I don't believe that you're so cold-hearted that you would condone an entire extinction, either. [Softer - she knows you better than that Zero. Inside, even if his heart is frozen, he isn't that sort of person.] You're kinder than that.
[She takes a breath, glancing away to stare at the side of a building while collecting her thoughts. It's sad, the entire situation, and painful. Yet even if it hurts, it's no longer about her anymore. The picture is so much larger. Already there have been those who have been injured or lost their lives. All due to the cruel madness of that person.
After a moment she shakes her head.]
For a long time, Kaname has wandered further and further away from me. The paths we've taken have split apart. I can barely see him anymore, and what is visible is shrouded in a dark cloud of black.
[Her knuckles tighten at her side, body straight, jaw firm.]
I'll never sit aside and allow someone so powerful to hurt or abuse others. It doesn't matter the reasons. [Because it's never all right to intentionally end innocent lives.] I ran away from home once with the intention of finding and ending the terror of those who would abuse their power. That person isn't an exception. I'm going to stop him, and from now on my hand won't hesitate.