Basically: Reimu realizes casting Astron is useless because that didn't stop the abuse. So she thought of falling on the mister's head after casting Astron as to kill him. However after jumping she said "It's like flying in the sky" instead of casting the spell.
Basically: Reimu realizes casting Astron is useless because that didn't stop the abuse.
She's casting Astron to avenge her family which was killed some time ago. There's nothing about the technique being useless here, aside from it being a suicide attack.
She's casting Astron to avenge her family which was killed some time ago. There's nothing about the technique being useless here, aside from it being a suicide attack.
The pages with a black border are likely to be flashbacks in which Reimu had used Astron already.
The pages with a black border are likely to be flashbacks in which Reimu had used Astron already.
No, those pages serve as an explanation about Astron, which also includes that activating Astron is a one-way trip - using it will turn the yukkuri into a living and conscious but silent and immobile statue, so normally it's a forbidden technique. The fact that the Reimu is still normal and alive here means that it hadn't used Astron obviously.
Not fluently and my set of known kanji is small (I waste a lot of time just figuring out the radicals so I can find them in the dictionary). I didn't read the narration boxes at all, so I went with the assumption that black borders are often flashbacks.