Actually, that's how she invokes death; the mini-gun is invisible the whole time.
What if the canon relationship between Momiji and Aya is far worse than it actually is?
BTW, about my previous question... I think a better way to put it would be "What if in the final game of the series, it is revealed that the Moriya Conspiracy is the cause behind all the incidents in Gensokyo and that Suwako is the mastermind it?"
Eh, whatever...