We all default upon the things we do most naturally when we are confused. You cannot blame Sakuya for the fact that, when in doubt, she stabs Meiling in the head.
But Meiling is Eirin here apparently and she was told that Eirin was messed up in the head so she stabbed meiling but meiling is Eirin so she was stabbing Eirin which meant she wasn't stabbing Meiling but she was and yet she wasn't so was it on reflex or was it doing as told? My head hurts.
You are Sakuya, right? Meili-...Eirin is having problems in her head, so please help!Understood.What is it, Meiling? What's the ruckus?Kaguya-san!This is so messed up in so many ways!StabWai-...what are you doing!?Nihǎo!Who am I? I can't remember!Keep it together!