Quite possibly for the first time since they'd met, Rex has some genuine anger in his eyes. It's a quiet smouldering, but very much there.

"Who said that about you?"

The tone he says it with has a very 'so I know who to beat up' angle to it, because as little as Rex thinks of himself the reaction to Toki talking badly of himself is that someone has been making him feel bad about himself. That loud grave voice inside of Rex says it's just a way to keep up that false pretence of the promise to protect him but...