Chika's eyes widened as she heard that, her hands balling up into fists. "Why do they even need to do that!? You're asking people to turn themselves into something else and then to die! What's wrong with you?"

There was another thing that came to her mind though. "And if you're one of those who did this, then how are you still here!?"

Of course, she had no idea what Sin was, or why it would need to be conquered several times; just that apparently once wasn't enough.