What.
Please don't do that. Both waves of the first card are ridiculously easy if you know where to start. The third card can be micromemorized but it can be done easily with pure reading. The human and youkai patterns are slightly different. (As human, the bullets travel the same path, just faster.) I am almost always youkai when I do those, but the exact same techniques work as human too. (Third card as human I just sightread first try.)
I intentionally chose some weak shot types for these, just to demonstrate.
First card:
Youkai /
HumanThird card:
Youkai /
HumanDon't worry if you have trouble with Mokou's first card; it's one of her hardest. (As with any Extra boss, Mokou is pretty much all memorization though. The only cards you could reasonably be expected to capture upon first seeing them are Flaw of Forgiving Shrine and Phoenix's Tail. The former is easy; the latter is harder but it's pure dodging, so memorization doesn't help.)
Here's a replay of how I do it with Reimu&Yukari. Staying up high at the start makes dodging the red knives easy. Move back when things get tough up high; usually you can go behind two rows of knives or so. Yukari kills it fast enough that it doesn't get tricky. (I have no tips for when it takes longer.)
For Flying Phoenix (see
here to see the spellcard names I'm talking about), you need to misdirect the phoenixes so that you always have a path. You should never have to even get close to the phoenixes or the static bullets they leave behind.
Here is how I dodge it, but it's not the only way.
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Ugh, why can't I capture Source of Rains today? I could do it probably 75% of the time last night, but after nearly 10 attempts today I haven't captured it once. And it's not like I've gotten worse; I am faring much better at VoWG today than I was yesterday. What the hell.