The story isn't too hard to follow. The fall of kingdoms is a topic that's pretty familiar to Inigo, and while his world obviously doesn't have anything like lab clones, the description makes him think slightly of the Risen. Except the things Prompto is describing clearly weren't human from the very start.

But then Prompto continues. And there's the numbers. Inigo meets Prompto's gaze for another moment when the other looks at him before his gaze drops towards the numbers, staring at them. At least it explains why Prompto seems to be wearing a glove all the time, rather than it just being a unique fashion choice.

Though he's quiet for a moment, he speaks up again as he looks back up at the other's face. "Well, hold on a moment there. You say those things are ugly, but you're a pretty handsome guy! Not as handsome as me, obviously, but you're up there." He smiles, obviously trying to bring some levity into this conversation. Especially with how tense and worried Prompto seems. "And you may say some slightly dumb things at times, but calling yourself mindless would be calling you a disservice."

It kind of sounds like he's making light of it, but really, Inigo means well. After all, what he's just trying to say here is..

"I may not know much about your world, but.. I don't think a few numbers on your arm are going to determine who you are, Prompto. You are the one who's choosing what you are. You haven't betrayed anyone, right? You don't act like a mindless drone. You seem just like anyone else. Then who cares what you were at the start? What matters is who you are now."