[There's a blank spot in Kakyoin's life, a yawning void of horror that he will never, ever get back. Not just for a moment, or an hour, or a day-- there are months of his life that were taken from him where someone else spoke with his mouth and killed with his hands. It's ghastly. As someone who has experienced it, who knows exactly how horrifying it is and has a (by and large) functioning sense of right and wrong, it's completely understandable why Kakyoin is afraid of it.]

Then don't be. Just because you have the ability to steal someone's life doesn't mean it's inevitable that you will, or that you have to use your power in that way. Your ability is a tool. A frightening one, yes, and one that would be easy to abuse-- but even outside of what you just told me, not one that I believe you would use in such an evil way.

What happened to you was terrible. But because of that experience, you have a unique perspective on what it's like. If you choose to use this ability, or learn to master it, you would be able to wield it while thinking first and foremost about the people you control.

[He pauses, considering.] Not that I think you're in the wrong for not wanting to use it. I don't think anyone could fault you for that.