Robin is remembering this confrontation from three years ago (or “last year” in-universe).

Back in Rome, where the last Nazi vampire’s ashes flicker and go out.

Robin: It’s okay. He’s gone. And I’m not going to chase you, I promise. Are you hurt?

Yumi-chan (Japanese): D-don’t make any more fire…

Robin (thinking): !! She’s not a child at all! Not only that, she looks just like that Iscariot agent I fought in Japan last year. Back when I was still using Orbo. Before I knew what the Church did to me…

Robin (Japanese): I’m not going to hurt you. I’m one of the good guys.

Robin (thinking): Maybe she is the same person. Maybe she was also part of some experiment, and it left her like this.

Yumi-chan: Yumi-chan will be good! Please don’t be mad!

Robin: Shhh. Nobody’s mad. It’s okay.