ReimuB's Patchy battle is actually supposed to be the second-hardest of the four, with I believe MarisaB having the hardest.
As for Sakuya, just note that the hitboxes for the knives are round. Yes. They're round. Don't try grazing them. I believe Eternal Meek has a safespot in the upper-right spot on her sprite. As for individual cards, the only real advice I can give is to make sure you're out of danger from the stainless steel set, so you can concentrate on dodging the bloody set and the moldy set.
As for Sakuya, just note that the hitboxes for the knives are round. Yes. They're round. Don't try grazing them. I believe Eternal Meek has a safespot in the upper-right spot on her sprite. As for individual cards, the only real advice I can give is to make sure you're out of danger from the stainless steel set, so you can concentrate on dodging the bloody set and the moldy set.