"Knight-as-cloak... I haven't seen it before, but it's interesting," she says. "Surprisingly, hmm, passive for a knight metaphor. And the secondary association with the wings is interesting too. If I ever wanted to design a spell to let someone actually fly, I might call you up and ask you to stand in. That's another thing I like about chess magic, actually - it lets people stand as part of the spell without having to actively do any magic themselves, and they still contribute."