Tyrion didn't truly believe that as much as Rogers did, but he appreciated the man's sentiment. "If you so certain of that outcome, then I'd certainly endeavor to be by your side."

And Tyrion also appreciated Rogers's actually asking after his name! Not everyone would have the courtesy, but then this man did not come from Westeros. What an oddly fascinating place this 'America' must be.

"I've neglected that name for too long, I think. Best give Hugor a rest for now. Tyrion Lannister I shall be. But if you find yourself missing the other name, I'll answer to Hugor still. Or Halfman. Or Imp. No one's called me 'Imp' for a good while. I'm ashamed to say I miss that affront the most."