It's not me doing it at this point, though. It's just me following instructions, which any schmoe can do.
Yeah, but your playing skill is still one of the best around. Kind of like going for Touhou at Lunatic. It's pointless knowing all the "theory" if you don't have the skills to execute.
Either way. It's time. Incoming wall of text. This is what my theorizing does.
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想起「二重黒死蝶」 / Recollection "Double Black Death Butterfly"This covers especially Hard / Lunatic. Normal to a certain degree.
Replay containing awesomeness of a 0 power capture of said Spell Card. [its essentially a timeout too, and awesomeness is a word?; spell-checker didn't pick it up as an error]
Analysis: (ignore if you wish, and skip towards "
Result and Conclusion" for a summary of what to do)
Satori will release a
pseudo-random set of butterfly bullets. This should be ~100 at Normal, and ~150 at Hard / Lunatic. At Lunatic, the bullets have a tendency to land off-screen, which actually makes the Spell Card easier... somewhat. Faster bullets move further after all, in a constant time frame.
The bullets shot will spread out in 8 directions.
Since ZUN is lazy The
same spread of shots is shot in each of the 8 directions. In other words, of the full circle, only a sector worth 45 degrees is unique, with the other 315 degrees being a copy of the original.
i.e. It really doesn't matter where you stand; you'll end up getting the same waves. Unless you want to shift around for the 22.5 degree difference. The only notable difference is the overall direction of the bullets in relation to your position.The
inner- and
outer- bullets will be preset, and don't spawn at random locations like the
inter- bullets. These bullets form perfect circles (or octagons) around the casting point. The
median bullets appear to be preset as well.
The rotation of the said bullets varies by difficulty. There appears to be no difference between Normal and Hard, but the Lunatic bullets rotate around by an extra 30-40 degrees or so. Red bullets move anti-clockwise, and blue move clockwise.
Bullets move at about the same speed for Normal and Hard. Bullets at Lunatic move at a much greater speed, but not that fast as absolute speed.
In short, the phases for each set are
spread, stop, rotate. Both stop and rotate are marked with a jingle I believe.
Result(s) and Conclusion:For Normal and Hard, avoid the bottom of the screen. It is a
deathtrap if you linger there 80% of the time. Stay centered if you wish to end the Spell Card quickly, or finding yourself able to read and dodge bullets incoming from 2 sides. Alternatively, you can move slightly to the left or the right during each wave, and "flow" with the direction of one of the waves. This makes the Spell Card easier, but takes longer to capture, even to the point of timeout if you're not careful. Either way, repeat until it's over.
For Lunatic... it is essentially the same thing. Except the bottom of the screen is
a lot safer. Read the set, move to the appropriate position, micro-dodge, repeat. Just make sure you have a high awareness of your surroundings (bullets move faster and swing a greater degree). Alternatively, you may want to move with the "flow" of one of the waves, much like above. However, you will need to multitask both reading the sets of waves,
and micro-dodge, due to the nature related to difficulty.
Here's a recommended field of awareness from the replay above:

Compromise the field in accordance to your skill though. Wouldn't want you to clip bullets.
For moving with the "flow" of one the waves, you really only need to focus on one color of bullets. Go with whatever one suits you. By moving with the "flow", I am referring to moving in 1 direction (in this case left-right or vice-versa).
To trivialize the Spell Card by a certain degree, you can wall-hug, so that about
1/
3 of the bullets fly off-screen.
Generally, you want to be able to
move precisely while focused, and
predict the movement of bullets.
1. Hard Spell Card? Yes. But still not the hardest.
2. Is it
that BS? No,
Eternal Meek does worse things. It's shorter though. Oh, and the spread isn't BS; you just don't read it fast enough.
3. Any way to "cheat"? Sure. Bomb
right at the start. It will negate the first wave. Alternatively, die right at the start (by being over Satori).
Remarks:-Hard's version is more difficult than Lunatic, in my opinion.
-of the 26 attempts (2 were used to unlock Practice Mode), 3 were captures. 2 were timeouts, each with 1 death each. Many of these were actually also me just screwing around with the Spell Card, working it out (~13). This was on Lunatic.
-donut had the right idea on how to do this initially... if I recall.
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Now looking for another Spell Card to analyze.