[there's a pained expression that crosses his face.]

It's too late to turn back now. I wanted it to be you and me in the very end, I really did. But... as it turns out, changing the world has its costs.

[he sounds pained as he says it, too. he loves his sister so much that it hurts... and it hurts that he won't get to see her grow up into the leader he knows she can be.]