Huh... if Zanmu is really the same Nichihaku Zanmu, then her Buddhism would be Rinzai Zen. So while still Mahayana like Byakuren, it's a whole different school of thought – both stemmed from China though, Zhēnyán and Línjì.
Huh... Reimu's ability to fly in the "air" is actually really special. 空 can also mean emptiness in a philosophical context. It is impermanence. It is detachment. Reimu's true ability is not flight. It is to not be bound by anything. Kinda like the Heroes of The Elder Scrolls. Or Xiaoli from Baki.
And then we contrast Reimu's impermanent void with Zanmu's nihilistic void.
