Interesting question, he imagines its very relevant to her world, but he can see in her face she knows it doesn't translate to here, or his own. But he can at least answer it.

"None. But I haven't met any yet so it's not for lack of trying. If we translate that to non-human monsters bent on attacking me? Five. They were creatures from Vrenille's world that turned up here. I don't know how many people I've killed."

He knows that sounds bad, but he's telling the truth. As an assassin, you can't carry that with you.