Man people don't have shit for reading comprehension. Anna thinks Maria is still living completely by her brainwashing, that she hadn't broken free. Then when she sees her eyes go completely cold there at the end it reinforces her thoughts that Maria is still Shue without realising that she is now Yuki, someone who has grown past those days of murder. She doesn't know that she spared Grace for no reason other than not wanting to murder any longer.
So when Hitoyoshi and Anna met when they where younger that was Nazca getting her Katsuta sauce fix? Tbh, I thought Nazca and Anna where closer in age. She is cursed like Naka, wonder if it makes her look younger? Or maybe she is only part human like Hitoyoshi and Riko? Would be funny if she is their aunt or something lmao.
It was always like this? Like we knew that Yuki's past was super messed up from early on.