started ranting abt this to a friend… i’m still so irritated that they didn’t include this
It also emphasizes how different this is from the magic we’ve seen from her before. Like, it was a major, albeit comedic, plot point that her water walking spell doesn’t even work if your hair is too dirty. She isn’t super particular about hygiene just because she likes to be clean, or thinks it’s icky otherwise, this is a serious practical concern that her magic doesn’t work as well without that purity. A difficult spell, requiring precision and with high stakes for failure, you would expect her to spend an hour beforehand fastidiously sterilizing everything involved like she’s about to do brain surgery.
But this isn’t that kind of spell. This spell is playing by an entirely different set of rules. This is magic that was created by, and for, people who are soaked in blood.