She isn't intimidated by that gaze, she's met it plenty of times before. Ritsuka can stand her own ground when it's something she believes in, even if, as it happens, that something is concern for Gil's wellbeing. Which is probably as strange a sensation for her in some ways as this situation must be for him.

"He was."

A simple agreement. But that's just the start. If he'd been reading about his past, she can think of only one thing in particular known to upset King Gilgamesh. Rather famously so, in fact.

"Except for a time when he wasn't, of course."

She definitely has a suspicion at this point, the question is whether or not she can get him to confirm it.