[Deckerd doesn't know what to say at first. He stares down at his datapad and he is back in that room that had used to be his whole world, except for Yuuta. Trapped in a room where the only exit meant leaving himself behind]

The whole world turned into shades of brilliant white that shrank from the outside in, until the only thing left was my knowledge of my own existence. That I was alive, and was loved. That I had given courage as my last and only gift. And then there was nothing at all.

...But that isn't what you are looking for, either. You want to know if it hurt. It did, inasmuch as having every part of your sense of self deleted one by one to make room for a stranger can be said to be something we experience physically. It hurt. And by the time I thought to cry out, I no longer knew how. And then I didn't know anything.

...Sometimes I do wonder if-

[A pause]

I hope this proves helpful. And I hope... I hope you know that you can ask me such things in person in the future, if you choose to.