[He stares at her for a while, still stunned. Why is she so worried about this? There's something missing here, clearly. Whatever it is, he squeezes her hands in return, once he catches his mental balance once more.]

Saya, first off, becoming like him is partly choice. And the other part.... [He hugs her then, just as his features harden, and the tone of his voice darkens, lowering. He wants to kill the people that hurt Karl to begin with. The idea of whatever Karl endured (hadn't he mentioned experiments at one point?) happening to Saya caused Setsuna's heart to beat furiously.]

I promise, I won't allow it. I'll die first.