She said that, but a Magus should be able to take care of someone like me easily. Hypnosis could
make someone’s memory hazy. If you had something which was called Magecraft, I think it would
be able to do more than that.
When I expressed such a question, Touko-san nodded and then gave me a paradoxical answer.
“Let’s see now, if it’s just someone’s memories you can do almost anything. Within Runes there’s
even a specific carving called oblivion just for that. But the time when that worked is long past. In
the old days it didn’t matter if there was one or two people who lost their memories. They were
considered to have been fooled by fairies or something and the matter was passed over.

Kara no Kyoukai: The Garden of Sinners, Volume 5, Spiral Paradox 6 /11