[Katsuki is almost too eager when he nods in response to Izuku's question. There's some parts of the battle Katsuki himself doesn't know, and some injuries and casualties that he does. But for Izuku's sake, he'll keep all the grizzly details to himself. He'll keep it all buried deep inside. After seeing his reaction to Katsuki's arm... he can't tell him everything.

And he can't let him know that Katsuki doesn't know the actual ending to it all, either. Otherwise Izuku's worries will prevent him from believing that everything was truly okay in the end.]

We did it, Deku. It took a whole lotta guts, and a whole lotta will power. But that bastard is gone now.

[This much is absolutely true. All For One will never, ever, be walking on his Earth again.]

He ain't ever coming back. And... if you ask me? I got really damn lucky coming outta' that fight with most of my body in tact.

[He knows this probably won't help Izuku feel all that better about his arm, but still. He makes this point anyway, his left reaching to gently touch at what was remaining of the right.]

It... could've been a lot worse.